That is crap. Users with 2006/2007 machines do have the right to complain, especially with Apple's extortionate prices. As for old tech getting in the way of innovation, bull, plain bull. It's no skin off Apple's nose to add a few extra drivers for older hardware when feasible. They have made an arbitrary cull at the software level, this forces the choice out of the hands of users and forces them to either fall behind in OS terms or buy even more expensive hardware.
I will be mostly unaffected by this (our oldest white Macbook has developed severe case fractures anyway) but I can sure understand any fellow Mac user who is furious about this.
If Mac Mini's are so cheap, are you going to volunteer to help others out who cannot afford to upgrade? I don't think so.