You can find rudeness anywhere, but it usually happens less often if you play somewhere that is not free (or free only to limited members, such as Chess.com).
Generally, you'll find better chess and less rudeness at chess servers than at gaming sites.
ICC, FICS, Playchess are chess servers.
Yahoo, Pogo, Chessmaster online are gaming sites.
Chess sites like Chess.com excel at turn-based chess, and offer a live playing environment that is far superior to what you'll find at gaming sites, but not nearly as good as the chess servers. OTOH, no software is needed to play live chess here (and that's the only reason anyone would ever play at Yahoo, rather than FICS). See the very old, yet still largely accurate, Yahoo! Chess vs. The Chess Servers.
Go somewhere unmoderated like youtube and you'll see that the abuse gets pretty spectacular.
Yeah, YouTubers are definitely the worst of all the major sites (not sure what else we should expect from tubers though)...
Well, they could be blowing unnecessary air into their tubes...
I mean, every comment I see is full of them vulgarities. Isn't there a mod in that site?