These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hate Dumb: Sweet fancy Moses, yes. Hara, Jiyoung and Seungyeon appeared on a variety show where Super Junior member Kyuhyun was one of the hosts. He (and the other two hosts) asked the members if there was anything they didn't want to talk about, and Hara mentioned her dating life (she'd been criticized by netizens for being seen in public with male companions after her breakup with B 2 ST's Junghyun). Did the hosts listen? Nope, they needled her about it until she snapped, and broke down in tears. Jiyoung was asked to do her aegyo (deliberately acting cute) and also cried, saying she felt uncomfortable. When Seungyeon was asked about the negative reception to her acting, she said it was because people were used to seeing her as an idol, not an actress. Netizens went nuts, saying that the group might as well be over with, that the only "good" members were Gyuri and Nicole, KARA was worse than T-ara, etc. etc.
An interesting thing to note is that none of the (male) hosts got in trouble (Kyuhyun, in fact, was praised). Two of them tried to stand up for KARA, but netizens just ignored them and blamed KARA for "forcing" the hosts to come forwards.
Replacement Scrappy: Averted; in fact, the most popular member of the group now is one of the replacements, Goo Hara.
Not after her recent scandal. The current popular members seem to be Gyuri and Nicole, with Seungyeon and Jiyoung being disliked, and Hara being the target of netizens' undisguised loathing.
Nicole's getting hate now because she's gone back to America to study, and never seems to be doing any actual studying. Netizens are resentful, saying she's quite average-looking, she "probably would have ended up working at a McDonald's in America", "she's not a celebrity anymore so stop writing articles about her"... Sheesh.
Tastes Like Diabetes: Honey, as the name would imply. It's more the concept than the actual song though.
Of course this is about the most subjective trope the tech demo evokes. Some people praise it for finally overcoming said valley, since Kara very closely resembles her voice actor and a real human in general (you can see the muscles move under her skin and her nostrils flare as she speaks). Other find that she still isn't human enough.