What kind of things does your Dad do on that laptop? It seems to me that Linux works well for people who are very technical and people who are not. The problem is with people who want to do more than browse the web and read email but aren't technical enough to do it on Linux. For example a user who wants to record themselves playing guitar. On a mac, plug in and open Garageband. On Windows download Audacity and plug in. On Linux figure out JACK/drivers/supported IO devices. I haven't used Linux in a few years so I admit my opinion could be out of date but I've definitely noticed that the problem is for that middle group who want to do more with their computer but aren't technical enough to do it on Linux.