As system admins, engineers and developers we can prefer security, restrictions etc. but lots of the people will prefer to run everything without so much questions (remember how people hate from Vista) This is why they use linux. Of course when they lost their files due to a virus they'll start blaming but still they'll not run linux, because it'll be a very complex system for them. Even so many businesses will prefer to run insecure systems behind a firewall. Because when they install the new security patch so many applications will not work, will take a long time to fix and nobody can answer the claims. With current business model is it possible to dominate the desktop of average Joe?