I think it's more about trying to change particular industries. If all of Adobes software was available for Linux in a supported and stable versions, you could see changes in the OS used in lots of design and creativity industries, which again would change what OS people use at home.

Also I think the force of being open source and spread over so many distros, is also a weakness in terms of getting the mainstream user to use it. My dad will call me or ask his friend about how you do this and that in Windows, but if our OS per default looks different from what others are using, he will not be able to get the same kind of help from his near community, and will have to rely on a more technical kind of support.

And things have to work out of the box. If I hear "You CAN get it to work" - I won't use it. I need things to just work, I don't have time to (nor interrest in) spending a night mingeling with config files to have simple things do the things they're supposed to.