Sounds like a perfect audience for an OS with fewer security flaws.
I thought the same thing after supporting a family composed of a ages 6, 13, 18, and 40+. I set them up with Ubuntu after hearing that they mainly use the computer for internet and email, as well as occasionally typing reports and changing the music on their iPods. Ubuntu did solve the malware problem, but it introduced several more challenging problems I did not see coming:
- OpenOffice saves in it's own format by default. Try explaining this to school children when they save their homework and then can't open it at school.
- iTunes does not work. Try explaining why the exact programs they are used to using do not work, even though alternatives like Rhythmbox work just as well. (I installed and showed them Rhythmbox, and they thought I had just installed iTunes...)
I could go on with several more specific examples. What it comes down to, is there are so many very small differences between Windows and Ubuntu (and likely anything else) that the users were very lost and confused. They had more questions and more problems, which have thus far been impossible to solve. The problem has changed from one that can be at least corrected with software to one that requires educating the user.
The average user does not want to be educated. The average user wants whatever solution requires the least effort on their part. As long as calling you to solve their problems is easier then solving the problem themselves, they will continue to call you. I have solved this issue by looking at all the computer repair places and the like in this area to determine what the charge and what their turn around time is. I offer friends and family a much better deal than anywhere else they can get their computer fixed.