Okay, Hunters is being labeled by many as the weakest season Digimon ever had. After watching it I can't deny said statement, it is so empty it hurts.
It had a good start bringing a new setting and new concepts, but then the following episodes failed to exploit it. The show got stuck in a boring repetitive formula, featuring no lasting plot-key elements (barring episode 14), no significant character development for the main character and no changes to the status quo until the very end. After some weeks you eventually catch the formula and start watching it with indifference because you alrealy know there's nothing to expect.
The other problem is having a generic static character as the main lead. I'm not asking Tagiru to be the last survivor of a royal lineage of protectors of the galaxy or anything like that, it is okay for a character to have no fancy background or direct connections to the bigger plot. Takato and Takuya didn't have one either. But he still needs something to make him worth watching, Tagiru has no interesting character traits and never got any significant character development, he is a dull character thrown in a Mo TW
based season and it makes him stick like a sore thumb.
To add insult to the injury he is the main lead and many of the already boring enough episodes are focused on him. It resulted in many of the other characters getting Demoted To Extra
, some of the new ones like Ren
never got an actual chance to shine.
But why it happened? Because Hunters was most likely not in the original plans. If I remember correctly Xros Wars was originally supposed to run for 52 episodes, then modified into 54. I don't know why they suddely decided to stuff more 25 episodes in the continuity, but it is said Toei was needing more time to fill the timeslot until Seiya was ready and demanded more episodes
. Or So I Heard
You just don't make a good sequel from scratch in a few weeks, it recquires planning and they had no time to do so. The final result was that, a succession of one-off stories with no depth, featuring a void character as a protagonist and the return of characters from previous seasons as a cheap gimmick to hold the audience.