My Dad got hit with the same. He simply installed a recovery disk I made for him and he was good to go. I didn't even know about it until all was said and done. AND I didn't have to spend time showing him how to use Ubuntu and I don't have to worry about random phone calls from him asking me how to do things with an operating system he's not familiar with.
He would FLIP if I tried to make him use Ubuntu. Many older people are very resistant to change and he would inundate me with phone calls to whine and cry and complain until I put Windows back on for him. I think most people's parents would be like this.
It's great to hear that your parents accepted what you did with open arms, but most people aren't like that. Also there are few programs that are natively supported by a Linux environment so your solution would actually work for very few of us.
Actually nowadays you can do most things on linux that you can do on windows. While your recovery solution was admirable your solution required you to spend the time proactively and you leave yourself open for another and another attack. The worst ones being malware that remains hidden and just silently steals data (internet banking, credit card purchases).
Knowing my parents usage patterns I knew they'd have no trouble switching to linux. My mother was very much against the change, she claimed she won't be able to learn to use it at this age anymore. About 15 minutes later she could do everything on linux she used to do on their old XP.
Receive/send e-mail: Check
Watch/edit pictures: Check
Watch/edit digital home movies: Check
Sync phone with computer: Check
Play flash games: Check
Handle office documents: Check
Skype: Check
Facebook: Check
General internet browsing: Check - and as added bonus no 'scary' sites anymore. Installed noscript on linux too though.
My step-dad has always been interested in coding and now he has multiple open source tools available through Ubuntu app store. They have multitude of music options through Ubuntu One (commercial and free).
To be honest I would have bought them a mac if I couldn't do this free of charge.