I've played on an RP server on WoW for about 6 years. The RP takes place behind closed doors and in less frequented areas. If the server wasn't labeled, you'd never know it was RP.
But I do think the stigma keeps jackasses/kiddies away for the most part. It's the friendliest server of the ones I play on.
Courage is not the absence of fear but rather the judgment that something is more important than fear.
The brave may not live forever but the cautious do not live at all.