No post-counts, sign-up dates, recognizable handles, identity, visible administrators etc. make it largely free of ways to criticize, or shield from criticism, people beyond what they themselves contribute.

"oh hai I see you have three posts on this board... n00b!"
"MisterCoolIce signed up in 2003, he's been here far longer than you and as such his opinion carries far more weight."
"I see you are a moderator, so accordingly I'll modify my treatment of you and kiss your ass at every opportunity."