oH boy.
I didn't get a chance to download his walls!!
(hey, that is the first time I used that emoticon in a while)
I do critical words on skins and wall and screenshots, and other stuff. I try to be constructive with it and not put the person down.
I also try to explain why I like something too; but most of the time I just say well done or Good Work (or Great Work).
I think the problem is:
a0
not knowing when to change the mood of the conversation on the board and knowing when to stop or take it to email or IM

Not knowing
how to be critical of something. it is a technique to it.
Also there is a pointing fingers of blame as to the downward fall of the board, but many can be blamed for that (even me

) and its not just the visitors or the admin.. a little more of both.
Also keep in mind that things go in cycles. There will be days where stuff gets through, there will be days where it doesn't. The message board also will go through cycles.
The real question is, are you going to help and change, or leave and let something you like self destruct?
If there is help needed as moderators, or you think they need help, then try to do so and contact them.
If there is a need to open an issue and discuss it, open it in a way that will hopefully spark ideas and constructive opinions. If someone post something 'wierdo' then try to help by streering the convo back to its origins.
The first place to change the enviornment is to change yourself.