I use Windows, because as much as I would love to be using an open source desktop OS, the way Linux systems are structured is a really terrible fit for how I use a desktop.
For brevity, let's stick with just application management as an example: You can't install two versions of the same application in the vast majority of cases, you can't move applications, good f'ing luck if you want to install something not in the repository, a version newer than what's in the repository, etc.
There's a reason there's so little non-oss software support for Linux.