Genuine tech enthusiasts with money, such as Steve Wozniak, love to dabble with non-Apple products all the time. Heck it wouldn't surprise me if Cook was using a beta build of Office 365 for Mac right now...
MS just shows that they are a superior brand and they dont treat others like apple does. There is recent thread in these forums where Dev decides not to go with Apple. Reason worth a read.
Just because a model works for a fashion label doesn't mean they buy those cloths
Just because an actor lands a staring role doesn't mean they love the show/movie