Constructive critisism is helpful and indeed quite useful, sadly most critisism is usually just opinion presented as fact.
E.g. "I don't agree with these bans, they are outside the defined ruleset and are open to wild interpretation. I would suggest clearly defined reasons for each ban to be posted."
vs
"These bans are stupid, the admins are just banning people they don't like. They're just a bunch of power mad egotists!"