Valve also basically have the entire PC gaming industry pay them rent. They could just work on Steam for the next 100 years and not want for money. That creates some pretty bad incentives, which coupled with their very informal management style can lead to the current situation. If rumours are to be believed, something is being done internally to address the problem and turn them back into a videogame company. I would personally love to see the Steam team split off into a completely separate entity, but I can see why that won't happen. In short, Valve's premiere product is a software delivery platform, and they sometimes spend some money to make a videogame. Sometimes that videogame even gets released.