Proponents of mainframe/time-sharing/big computing opposed personal computers pretty strongly. To them(e.g. John McCarthy), it probably seemed like computers are there to be the big-brains, sort of oracles, humans should seek help from solving complex problems like AI. So, relegating majestic computers to companions filling people's desks/pockets was not acceptable. From a historical perspective, coming up with the idea of personal computers, with TX-2 to be the first actual PC followed by PARC's ALTO, and amid all the drama and money poured on developing big machines(lobbied by big names), was the PC, along with its metaphors: GUI, desktop publishing, ..., something that could have been invented by anyone easily?