@attila77: what's wrong with using market penetration and availability as part of your purchase decision? It relates to :

- potential industry support\compatibility with said platform.
- number of potential 3rd party apps and accessories available for it.
- number of devices you can 'surely' interoperate with.
- size of audience, if you're a developer.
- potential lifespan of the platform.
- etc.

Unless all linux users are antisocial hermits, I think it should be obvious that popularity isn't bad.