Interesting idea Peter. But is it the RISC OS applications that keep people on the platform, or the OS itself?
Most of the big RISC OS apps have been ported to Windows in some form (Messenger, Ovation, ArtWorks, Sibelius, PipeDream....) but we still have a following using them on RISC OS - probably more than use them under Windows.
So I'd argue that the OS itself (stabilty, WIMP etc.) is the bit that keeps people on the platform, paying OTT prices for hardware etc; not the applications.
The same could be said for Linux - most of the popular Linux apps work under Windows too, but people still use Linux.
Also, you can get much better editors than StrongED under Linux/Windows!