AFAIK, most of valve’s stock is held by employees, not private investors. It’s usually a pretty hard sell of “make the company you work at shittier to make more money”, especially since most of the employees probably know gabe personally (valve has less than 400 employees) and likely approve of his leadership.
yeah, its hard to predict what will happen to it, especially after gabe steps down or dies, but depending on how much of the company is broadly owned by employees vs individuals, it can help to shield it from bad decisions. Unfortunately, we don’t know the exact numbers. If gabe + mike own 51+% then it could potentially lead to overriding employee will in a bad decision for money (either through their actions or through inheritance like you say). Or the employees could just collectively make a bad decision too.