Because gamers are a community well know to spend several hundreds of dollars easily for any kind of upgrade to their existing hardware. At least the core PC gamers, and that's quite a large segment nowadays.
It also has to do with enterprise products suck.
People's workflow is often fairly static, and this would need to fit the existing requirements. Games are very different from each other and transient. This may not work well for most of a gamer's library, but new games might come out that they will buy and utilize. If this doesn't work well (or even just as well as what you currently use) for a browser, terminal, spreadsheet and text editor, are you going to switch to some new software that you don't know that might work better (but still possibly not as well as what you used originally) just to make use of it? I wouldn't.