The only thing stopping me from making Ubuntu 12.04 my main OS is that a lot of programs I use on Windows 7 and Mac aren't available for download on Ubuntu.
Why don't popular programs like Photoshop or World of Warcraft support Linux?
Also, would a company have to create the program (eg: Photoshop) for every possible distro (Gentoo, Arch Linux, Ubuntu, etc...), or would they just have to make one binary and it would work across all distros?