Earlier quoted context omitted.
Well, you make it a game - people start playing. The disadvantage of gamification. I'm not sure that people giving good answers and help are well matched by a system designed for people who like "leveling up". I think that system pulls in a mismatched crowd over time, too focused on the game goal. The solution creating a match is supposed to be what you get the points for leveling up for. However, that does not reall…
they aren't "purely virtual achievements", they're, as you say, points in a game. i can (and have) spent hours at a time playing scrabble or civilisations, and they aren't for "fake scrabble points" or "fake civ points"; similarly here, for the people who do get more into the gamified aspect of stackoverflow, they aren't chasing fake internet points, they're accumulating real stackoverflow points.
You get to keep everything that you achieve in your own head, like "having fun" or whatever satisfaction you derive from what you do on those sites. You don't get to take out anything you manage to "create" their though, like your level and points. So except for what you manage to do in your own head it's much-input-no-output, a black hole box that swallows all your efforts and keeps them without giving back. Again, speaking about the "game", not about your own satisfaction e.g. for helping others.
The game is used to pretend to you the rewards are higher, but in order realize that promise you have to stay in the game world because the rewards you earn cannot be taken out.
So yes, within the context of those sites it is "real".