Some people just arent very serious chess players and they will never " get it ". Its useless arguing with them as it is with a box of hammers.
The vast majority of chess players aren't "very serious chess players". But then, whether or not someone is a "very serious chess player" is completely irrelevant to the discussion, either way.
Nice try, though.
I don't like to agree on the point that gg is arrogance, although I agree that it isn't very friendly, or nice to just say it at the end of the game without a hi (although blitz games I find communication is like a deliberate distraction); even occasionally, I find the same in standard games.
In over the board play, it's customary to shake your opponents hand after a game. Or at least it is in some time, or place. gg is like that in a way. It's automatic, and only done as a sort of custom between people who want to follow the social rules for politeness.
Some people might use "gg" in the way you think, but you'll never know when that is from the letters "gg". Honestly, how do you know what goes through the players mind when they type gg? I think gg is used to get the message across "good game" in a quicker, and easier way, so to conclude the game/"interaction" before the opponent leaves chat.
I agree that it is used in a mechanical way as well. In otb, you would expect a little more courtesy, but that's a little over kill for the net; beside that, there are so many rude players here to deter members making the effort for every stranger they play on line.