That's not fallacious at all. I imagine the guy above knows valve aren't a selfless charity.

There's a guy in my area that goes around with his pressure washer and cleans grimy road signs, park benches, etc (because the council doesn't seem to give enough of a shit to do it themselves!)

He does it because the goodwill and publicity he gets from it benefits his business (he cleans everything from walls and houses, to wheelie bins and industrial/farming equipment).

He is not acting out of pure altruism, but does it really matter? His/Valve's actions are still benefiting people regardless.