Managing a computer company involves making computers more than once every 3 years.
I sort of feel bad for Apple, because really there haven't been a lot of substantial improvements in CPU tech to speak of, so they're forced to ship random crap. Apple probably has some threshold or another for when they can throw away their tooling, which means they can't really cycle through ideas quickly; their metrics and processes are based on making tens of millions of devices, not hundreds of thousands to a few million.