Just because in the OPs opinion people behave like this in every other game, doesn't mean that it's "OK." What people still do is extremely rude.

My only MMORPG experience before this by the way was FFXI and pretty much the worst insult I ever received there was "you noob." Then ARR came along, I logged in and was like HOLY SH*T, people are bonkers! Then I was told it's common in games since WoW... Well.. Okay. But still not fun.