Distribution of labor and specialization works better than consolidation. Apple might be able to build its own chips, but likely it's better just to leave chip building to the chipbuilders, and when one falls behind, just switch to the next--that's what Apple's been doing with Macs for years. Motorola -> IBM -> Intel -> ?
If Apple built their own chips, they couldn't very well switch to someone doing it better, now could they? What happens if Apple builds its own chips and then Intel releases something twice as fast for half the price? Apple would be stuck with inferior technology and an albatross of a production line. It is naive to think Apple could do it better forever, since it seems no company seems to be able to stay in the lead. It's better then to have the freedom to dump a company that stops creating competitive products.
I disagree. You seem to be arguing both sides of the point. Plus, you seem to be confusing chip design with the fabrication process.
Why has Apple had to move from one platform to another? Because their chip supplier's failed to deliver what Apple wanted/needed.
Sometimes it was technical reasons, but mostly it is because each company has it's own priorities and those may not be in line with Apple's. You think Apple likes going through architecture shifts? 68000 to PPC, then PPC to Intel, then iOS on ARM. These were not fun side projects, these were all necessairy evils.
Moto wanted out of desktop processors, IBM wanted to build chips for Blade servers and didn't care about low power needs in notebooks, Intel didn't have a mobile-ready play, etc.
Apple has publicly said they believe they should control the key technology in their products. That is why they have purchased PA Semi, Intrinsity, and Anobit. Apple is now fully designing their mobile CPU, based on ARM architecture.
All that is left is the fabrication process. I'm all for Apple building fabs and controling this end-to-end.
Folks said Apple would fail miserably at retail and we all know where that went...It's time for Apple to reinvent manufacturing. The icing on the cake would be if at least some of these manuf jobs could be in the US.