But the OP is right in that the vast majority of computer buyers never upgrade aything more than RAM, if that. That's why Apple sees no need for a midrange tower.
precisely. this was more a comment on the computing world in general, as I work in a PC environment with a couple mac users sprinkled in for good measure.
the argument that iMacs arent upgradeable and the mac pro is too much money just to be able to upgrade, just doesnt hold water. sure its a good future-proof method to be able to slap another PCI card in there or another internal HDD, but most people just dont ever do this. and those that do, are the ones who could use the power of the MacPro.