IMHO, the reason that there have not been as many conflict problems with the MAC platform (crashing and the sort) is the problem that we're all understanding. Limited software products that were being made for Apple by the software vendors.
In a way, the ability of MAC's to run Windows products is a corporate admission of that very fact. The only way to get support was to give in and make their platform dual capable. And even in this, they still will fall short.
My Win XP clients have become competent in system operations. Crashing is minimal in the over 8,000 machines that I can directly speak to. And let's be clear, crashing totally is what I am speaking to here. On my personal systems (at home and in the office), I have not crashed for over nine months easily. And they are all used heavily.
Here is another factor, MAC is home on MAC. Windows is home on Dell, HP, IBM, Toshiba, Sony, Acer, etc. Problems should be expected for that very factor. Anyone try to run the MAC OS anywhere else? Successfully? Unix, Linux, and the various flavors are all more competent. But they too suffered/suffer from vendor support as it relates to the masses.
As it stands, for most of the world and the universe of work right out of the box programs, there is only one flavor. Grin Mr. Gates!
