What if I keep doing these kinds of projects? Will I eventually lose the popularity contest and be ousted?
The amount of money to be made in personal robotics or space robotics probably dwarfs what Valve makes now, but research is risky.
The combination of employee selection and social pressure means that it's probably not really true that you can work on whatever innovative ideas you want to.
This is what irritates me about companies co-opting hobby time and free time. It's not really free time if it's a popularity contest. You don't have to justify your hobbies to anyone (family, maybe).
I work at a company where I have tremendous freedom to organize my own work, and to work on research projects, but there are still areas that are clearly out of scope. I imagine Valve is no different.