I'll start
I hate MLD for sexualising the then-minor members in Momoland and not putting safety shorts on either of them while the rest of the members had them, while giving them the tiniest shorts which were often a size too small because the girls were curvier than the other members
It was so clear why the company did that and who they were trying to appeal to
I also hate them for what they did to Yeonwoo, she was an acting trainee that they suddenly told she would become an idol instead because they found her pretty, she had no confidence in her skills and didn't think she was talented or a good fit, she worked extremely hard and had a big improvement, her dancing and performing got a lot better and her vocals improved and she was much more stable and you could tell she was working hard on training and they took her out of the group without her consent and against her wishes so they could cash in on the popularity she got in acting