I bought a Linux eee PC, within 3 or 4 months I had removed Xandros and put on Windows Server 2003. Never looked back. Lots of retailers also find that Linux machines have far higher return rates, complaints and issues with support (I believe it was MSI who had an internal report where their Linux machines had double the return rate). So people want Windows, not Linux.
Developing commercial games for a Linux platform is also nothing new, there are several companies paid to port mainstream titles to the OS. But it’s a tiny niche section of the games industry creating games for a tiny niche OS (niche for desktops). There is very little money in it. Plus the majority of Linux users aren’t that interested in games (or at least not as much as the typical Windows users).
Another issue for me is that I’ve always found Java runs consistently best on Windows (for example the not too recent Direct3D pipeline for Java2D), and Windows machines are typically the best setup (they typically always run the Sun JVM and always have good graphics drivers installed). I’ve also had the least number of OS specific bugs on Windows. So I’d prefer to target netbooks running Windows then Linux.
Chrome OS might swing it. But currently it looks like any other Linux distro, except with Chrome.