Windows gamers and reviewers seemed to not realize AMD cpu performance was nerfed on Windows until the latest gen AMD release. From time to time there have also been issues with Windows scheduling for Intel cpus. Including a competing OS in comparisons allows reviewers to sanity check stuff like that. Wendell had the most balanced reviews because he was presenting cross platform and productivity along with Windows gaming performance. When Microsoft held a monopoly that sort of reviewing wasn't possible. You had no idea if Windows was nerfing particular platforms or why.

Overall Linux gaming might be worse or some titles really bad but lets get it out in the open. It will be good for all consumers because it will drive improvement.