Bacause MS Money is still the best personal finance program for us Brits; Because the LDS church don't make a mac version of their excellent Personal Ancestral File program; Because my Canon D660U scanner won't work under OSX; Because sometimes I just have to use MS Word and Excel even though I have NeoOffice and Pages; Because I just love all the hassle with Anti-virus software, the joy of editing the registry, the excitement of getting unwanted ads, etc, etc. OK, I lied about the last bit, but, in short, I run windows because I have to. I'd rather I didn't but until someone brings out a half decent finance program that knows how to spell cheque, that will enable me to organise my family tree without a lot of extraneous (US market) information, until Canon bring out a driver for my scanner and until Pages/Neoffice can process labels, tables, formatting etc interchangeably with Word (or I buy Office for mac), I'm stuck.
Good question BTW.