You can thank game devs and cheaters for that, primarily. Laziness for the first, malice for the second.
I think it would be fairer to say that it doesn't get prioritised, especially over anti-features such as microtransactions, DRM or things of that ilk. Calling them lazy is disrespectful, hurtful and betrays a lack of understanding of the development process and the industry at large.
- massive front-end visual dev, both static and animation, that often require logistics and endless fiddling to get it just right - hefty back-end dev, especially when dealing with massive latency questions (e.g., MMOs) and calculations (e.g., 4X strat) - audio design that must sync with graphical elements - on top of all that, higher standards for input syncing to video output than almost any other type of app
...and then overworked and crunch-time to top it all. I'm amazed that we're even getting finished games these days now that devs can sell a near-playable v0.6 as "Early Access"!
I understand linux support takes time and it usually isn't worth it. But this is just flipping a switch from what I've heard.
Even then, I would be reluctant to call it institutional laziness. Businesses strive for efficiency. Can not doing a high cost thing be called laziness? Sure, but I think it's still disingenuous and misrepresents the issue.