I haven't seriously tried to game on Linux in a number of years so this may have changed, but every time I've tried I get some kind of horrid tearing or stutter or low frame cap across a number of games that seems to be caused by inferior graphics drivers.

If by "developers" you mean the ones working on the unity engine or Nvidia proprietary graphics drivers then you're right, but in my experience there are a number of problems and pitfalls further down the stack which game developers can't reasonably be expected to mitigate.