You're right that it's a common misconception that games don't work on Linux, and that misconception needs to be addressed. But playing games occasionally is such a common thing that you can't treat them as one homogenous group. "Everyone" plays games. But many many of them do other things as well on their computers, and many of those would consider the other thing more important than the games.

People who use the Abobe suite for example. Digital media creation in general (massive group of people btw) is subpar on Linux. Personally my biggest hurdles right now are DTP software and a specific piece of music production software+hardware combination from Native Instruments.

Not to mention that most people are not ready to deal with a Linux installation that is having issues.