If I can run all my games under Linux, I'm probably going to switch, the end. I'm not the only person thinking like that (it's probably still a small minority, but I imagine higher than the 0.5% of pure Linux gamers). That's reducing monopolization right there. Now it probably wouldn't usher in a giant WAVE of breaking, but it could maybe bring Linux up to single-digit percentages if there's no reason a gamer HAS to stay on Windows.Not exactly sure how making native Windows code run under Linux is breaking Microsoft's monopolization. It's very possible making worse by discouraging developers for making non-Windows native content.
And give me a break on making things worse. It's never been easier to port to Linux. Any developers not releasing a Linux build weren't going to anyway. On the contrary,if Linux could get a more significant marketshare, that would provide more incentive to switch.