You're right, they don't need to make games. Yet they just released Alyx! Counterstrike 2 is known to be in development!

I don't play TF2, so I don't know what they're doing right, but people are still playing it so whatever they are doing is apparently just fine with a lot of players. Bots have been problematic in online games forever, I don't really know if that's a TF2 specific issue. In any case, they've already supported TF2 way longer than most companies actively support their non-subscription games so I'm not sure what level of expectation is fair really.

No one has to like Valve, but painting them as this evil force in the gaming industry is a little bit silly IMO.