I do understand people get emotional about this (my self included) because it means that if I have to move to windows for my workhorse, I will have to move my laptop use there as well as it would be too much hassle syncing and keeping to different OSs going.
I have a Windows laptop. The only pain is having to have both versions of the same program (like, MS Word.. or Adobe Photoshop!) Half the time you're not "supposed" to use the same program license on 2 different computers anyway.
The file sharing bit is actually pretty easy: You use dropbox or iCloud or old fashioned SMB file sharing. Drag and drop, and you're pretty much done.
Security in W7 is pretty decent too, not perfect but if you're using Chrome/Safari/Firefox you're about as well off as you are on a Mac (although, it's good to have a virus scanner for those thumb drives/emails! At any rate, Mac users SHOULD do this too. We're just lazy bums!)
Back on topic though: It would be a foolish long-term business decision to abandon your loyal business customers. If anyone knows this, it's Microsoft. Google has been trying to tap into that market for a while now, because alongside advertising it's pretty lucrative.
The consumer gadget market is very volatile; naturally, high profit margins come with higher risks. Part of the reason Apple was so successful probably has to do with their (seemingly short) attention span matching that of the market. Just as the crowd gets tired of seeing iPhones, Apple comes out with an entirely different one. Hrmm... they used to be that way about their computer hardware, too.
You cannot have all of your eggs in one basket - if all else they should be (carefully) expanding their Mac lineup in a smart way to provide more income. At the end of the day, as long as a product is generating a net gain for the company (after R&D, production, and all of that).. why the hell would they kill off a successful product?
At the end of the day, I think a small part of that probably lied in control freaks. Perhaps someone in upper management gets their panties in a knot over the idea of someone using a Mac with a matte Dell LCD... or an Eizo LCD.. or anything out of Apple's control!
Either way, the Mac Pro is a bit of a compromise machine. It is now being used for those that just want/need a tower, those that need workstation hardware, and those that need a server running OS X. Heh ,3 birds! 1 stone! It's almost as bad as eliminating all of the portables and only having the 11" and 13" MacBook Airs.