I switched to Linux because of Linux gaming. Yes, I am completely serious!
Back in 2015 I had Lenovo laptop with only 2GB of RAM. Windows 7 consumed more than half of that and DotA 2 took over 2 minutes to load the map. The game was laggy. FPS was terrible even on low settings.
On another hand Ubuntu 14.04 consumed only ~350 MB of RAM. DotA on Linux loaded map in seconds. FPS was slightly better, but the game itself didn't feel so laggy anymore.
Linux was (and still is) my only viable solution for gaming on low spec hardware.