I chose linux because it is what I use on a regular basis. If someone just wants a plug and play solution windows is probably the better choice. I want something I can customize the way I want it, not the way a developer thinks I should have it.
A carpc on Linux isn't easy there are a lot of hoops to go through. The biggest of all is a decent nav program. But if you want to learn something when you build a carpc vs just install a few apps and be done with it then linux is a better choice.