Ah yes, from one stupid forum topic to another...
gg is arrogance

JT, long time no see. The quality of discussion in the cheating forum deteriorated rapidly after the purge and subsequent lull. I gave up on it.

I had to give it up for sentimental reasons. I miss these guys so much, I want to cry:
'chita
'geek
fezzik.
Their expulsions make me as sad as the murders of Sacco and Vanzetti.

Well yeah, I've noticed that, it ain't what it was before but I had to get back in because the forum is bullied by a group of guys spreading falso info for true and saying amen when kohai speaks.

Here is an instructive "chat" during a live blitz game on here:
NEW GAME (352481528) - -Mohamed-Khan- vs. johnmusacha (10 0 rated) (win: 5, draw: -3, loss: -11)
johnmusacha: hello
-Mohamed-Khan-: hi
johnmusacha: gg
-Mohamed-Khan-: ok
johnmusacha: gg
-Mohamed-Khan-: gg
-Mohamed-Khan-: gg
johnmusacha: gg
-Mohamed-Khan-: gg
johnmusacha: gg
johnmusacha: gg
-Mohamed-Khan-: gg
-Mohamed-Khan-: gg
johnmusacha: gg
-Mohamed-Khan-: gg
johnmusacha: gg
johnmusacha: gg
-Mohamed-Khan-: sorry gota go dude
GAME OVER - -Mohamed-Khan- vs. johnmusacha - johnmusacha won by resignation (+5). Your new blitz rating is 1088.
GAME ANALYSIS - Analyze this game - with your opponent | alone
johnmusacha: gg
johnmusacha: gg

Wow! There's so much barely concealed rage and disdain there I can hardly bring myself to read the whole transcript. It's too emotionally draining.

You seem like a little "angel." ---> .... I certainly hope you don't try to Insult people by saying "gg" when you beat them!
I never do, of course I never win either!

I agree with KillaNinja's initial comment, sometimes it is arrogant to say "gg." If you're going to say it post mortem, you should al least say "hi" before starting a game; it's proper etiquette and even common courtesy to say such to someone before engaging in chess.

Isn't saying nothing worse than saying GG?
Not if you won. Give the loser a chance to start any post game communication. OTB I will always give the loser the chance to initiate the handshake. In CC chess, the proper thing for the winner to say is "Thanks for the game". It has a better chance of being appreciated, if you send it the next day after the resignation.
I'll claim it as my own skill for subtle hidden ploys! :-)