Simple for Slashdoters != Simple for everyone
Linux is simple. You just have to set it up (just like with Windows actually...). On my last laptop (about 3-4 years old now) I had Vista and Ubuntu installed. My wife could choose whichever she wanted. After a while, she was only using Ubuntu. She is an intelligent woman, understands computers from a user's viewpoint, but is by no means a computer nerd. And I certainly didn't push her to go either way. After some time, she actually managed to install a Wine application, by just clicking around. Linux works.
In my company, after using SuSE Linux Enterprise Desktop (which is a load of crap; mainly because of missing a gazillion packages), we switched back to Ubuntu and Windows 7. The Ubuntu users are happy, just as are the Windows users.