I think that the reason that Apple has stuck to one button mice for so long is because of simplicity. A single button mouse can be used by both left and right handed people, eliminating bias. The problem is now that even left handed people are crying out for more buttons. I guess the sight of the obligatory Logitech plugged into every Mac was too much for Jobs to bear so he caved in. I for one have been so much happier since getting rid of my single buttoned 'pro' mouse for my iMac.
