Arc Fatigue: Many fans got fed up with the Digimon Hunt arc by the time it finally ended, as it took an awfully long time for anything resembling a plot to really kick in. Said plot was first hinted at in episode 14, and only gets going by episode 22. At which point, there are only three episodes in the whole series left after that. This was made worse when the build up didn't really lead anywhere, just a team up with the older series' characters to beat up some mooks (which happen to mainly consist of VenomVamdemon and BelialVamdemon, mind you) and the generic shonen lead taking center stage to defeat the generic villain in an anti-climatic duel.
Critical Dissonance: This already happened with the original Xros Wars/Fusion, but this series had it worse; despite having actually beaten the previous series/season for the worst ratings in the franchise (and accomplished this feat enough to make the fandom rarely unanimous in that this was certainly the single worst Digimon season), Young Hunters received a nomination for Best Animation at the 2012 International Emmy Kids Awards.
Designated Hero: Tagiru makes it clear that he's in it just to become a superstar, and so does Gumdramon at times. Even when Earth is in danger of being destroyed after Quartzmon merges with it to allow DigiQuartz to rapidly expand and take over it, they're still more concerned about becoming superstars then the fact that, you know...everyone and everything they know and love is being assimilated into Quartzmon!
Ensemble Dark Horse: Kaoru, a one-off character is well-liked, having a nice bit of fanart to her name.
Fanon Discontinuity: Some fans think that Digimon Fusion, the previous series, had a decent ending with the defeat of Bagramon, and consider Hunters a poorly written and unnecessary addition to the series. Among the more common complaints are the Monster of the Week plots making up most of the episodes and the new main character — who is seen by many as too generic, uninteresting, or just plain annoying — receiving too much focus and overshadowing the rest of the cast with no noticeable or long lasting development. In fact, many people only watched it for the crossover finale that makes up the few final episodes, and even there Tagiru managed to fight the final battle alone.
Hilarious in Hindsight: As mentioned below, in Taiki's Rousing Speech he mentions that a hero needs goggles. While Masaru being there already proves the statement rather false, a couple years later, another Digimon protagonist would take action without any goggles either.
Ho Yay: Between Tagiru and Yuu. In episode 16, when Yuu and Tagiru are trapped in a phone booth together and a girl finds them with their arms around each other, they say that they are "really good friends". They were trying to divert suspicion, but still...
Many people only watched it for the leaders from previous seasons.
To a lesser extent, there are those who liked the original Xros Wars and only watched this series for the returning members of Xros Heart, who sadly don't get a whole lot of screen time.
Misaimed Fandom: In a strange case of the show not helping its case, this season was meant to be about Tagiru's self-growth to becoming a leader, which is sadly rendered moot due to the lack of an overarching plot for most of the season, Tagiru's Static Character, and the older series' leaders coming in, causing people to be more excited about that than what the arc was supposed to be about.
Narm: It's kind of hard to take Arresterdramon Superior Mode's debut seriously when Quartzmon's agent is literally making the ":(" emoticon as the former charges towards it.
Did you think the hatred for Daisuke was bad? You've seen nothing compared to the sheer level of loathing that Tagiru gets from some fans to the point of being one of the most hated protagonists in Digimon history, for quite a few reasons. The highlights (if you can even call it that) include his incredibly selfish motivation, unchanging character and constant spotlight hogging (which both result in nobody else apart from characters of the day gaining character development), how everything seems to go in his favor in the end, his unbelievable degrees of idiocy, and worst of all being that he gets to fight the final battle alone on top of being the only one to have a proper goodbye and reunion with his Partner Digimon.
Betsumon appears to attract a lot of hate from fans who find him just plain irritating.
Sequelitis: Young Hunters quickly developed a severe reputation for this, despite being somewhat promising in premise; Tagiru is the most obnoxious hero in the franchise, new characters are robbed of any chance of being anything more than one characteristic, and the show derailed the previous Xros Wars protagonists. Worst of all, it consisted of almost nothing but Monster of the Week filler episodes with nary a plot in sight, which was compounded by only having 25 episodes. Therefore, the show had no time to pace things out or get things started. Furthermore, it only gave the briefest tease of the Crisis Crossover twelve episodes in before seeming to completely forget about it until the last four episodes, with nearly all the prior heroes being Demoted to Extra so that they can serve as power-ups for Tagiru in the final episode. (Not to mention that there was a big missed opportunity in that we didn't get to see protagonists from the manga, video games, and other notable forms of media in animated form a la Kamen Rider Zi-O: Over Quartzer.) This case was actually so bad that it knocked the series off TV for eight years (not counting the App Monsters spinoff).
Signature Scene: In the penultimate episode, the scene with each of the legendary heroes from previous series showing up to save the day together. Even those who have never seen Xros Wars know this scene thanks to its popularity on the internet.
All three rival hunters. We never get any background information on them (what their family lives are, what motivated them to become what they are now, how Airu and Ren met their own Partner Digimon, etc.), nor are they at all developed personality-wise save for Airu (and Ryouma in the last few episodes). For many, this was disappointing due to their initial potential.
Similar to the rival hunters above, this series could have been a new opportunity to work out Dagomon as a powerful antagonist like a true Lovecraftian Digimon deserves, unlike his short-lived appearance in 02. Unfortunately, he only appears as a curiosity and is almost immediately forgotten.
No, there is no Time Travel plot (at least from the audience's perspective).
Many feel the Crisis CrossoverGrand Finale was vastly underwhelming since five of the previous leaders were reduced to living batteries for the Brave Snatcher. Due to everyone getting reduced to DigiQuartz, Tagiru and his Partner Digimon are the only ones left to fight the final battle, which basically boils down to Quartzmon hurling loads of square stuff at the both of them before being swiftly dealt with, Shoutmon taking Quartzmon's DigiTama (or Digi-Egg), and the Digimon and humans separated back into their respective worlds. That's it. Not to mention The Clock Man apparently revealing himself to being Bagramon and the open ending.
DigiXrosses, which are known as Xros Ups here (for the most part anyways), were rarely used here, despite being the show's trademark. And even then, most of them don't even get real names (which had always been a problem in the last season, but this one amplifies that), and the ones that do are — insultingly enough — joke DigiXrosses!
Most of the hunted Digimon never made appearances after their debut episodes — either for Xrosing or for fighting solo — and even the core members of Xros Heart besides Taiki and Shoutmon hardly made appearances.
Seeing the generals and their armies unite a year later, the mystery behind Digimon feeding on human emotion inhabiting a parallel timeline known as DigiQuartz, a competitive hunting game for said Digimon inhabiting said DigiQuartz, the old generals taking on a new hunting role, Gumdramon's development from delinquent to positive societal figure, rookies (not the Digimon kind) to the Digimon Hunt going into the situation blind (even with a handy-dandy rulebook in hand), and last, but certainly not least, a crisis requiring the meeting of teams from several continuities. Each and every one of these would have been a very interesting premise on its own and help win back the crowd after the lackluster reception over the last two arcs. Altogether, none managed to have their depth sufficiently explored, come to any fruition, or reach a satisfying conclusion in 25 episodes. THE worst ratings in the franchise history, too.
You could make an entire show off the premise of all the teams from previous shows crossing over, even if done in a way reminiscent of Kamen Rider Decade where the Original Generation explore alternate universes of past series, and yet they barely even interacted with each other, if at all.
