Well, most of the guys are teens that came over from other series like Naruto or Dragonball Super.
Very annoying of course, but they are young and need their fictional heroes that they can look up to and celebrate. That's why their reaction to any depicted flaw is always so huge. Flaws in their heroes can't be accepted. In addition, they try to mask their general insecurity by bashing characters they don't like.
It's the classic teenage behavior, nothing more, nothing less. After thinking about it, you can't even be mad at those youngsters.