I see the arguments and I love Linux and still would not set my dad up on it. I don't think it's ready for the standard home user. Most home users (IMHO) want to go to the store and buy the new XYZ software product take it home and run it. I know Linux has plenty of apps but with windows I just go to the store and there are hundreds of titles to choose from. Plus I get my favorite game running on it. Not an imitation.
Just my 2cents.
--Mithalas