With linux you have to do a choice, as in either Windows or Linux.

Most users have one laptop/desktop computer and they want to be able to do the same stuff as their friends.

Myself I'm mainly using Windows as it's what I'm accustomed to and most games are for windows. If more games were ported to Linux I might have gone with that option.

With BTC you don't have the same barrier. You can use BTC under any operating-system and the competition is mainly CC and paypal. When barriers against using BTC goes down, usage will go up. As more and more vendors accept BTC, more and more users will start using it.

I am not one to think that BTC will "overturn goverments and markets", but it might very well overtake paypals position and then some.