Brian Krzanich was the primary architect of Intel's demise. A huge amount of Intel's problems stem from opting to go with DUV rather than EUV light source for lithography, and this decision was made during Krzanich's tenure. This may have stemmed from Krzanich's lack of technical expertise. Gelsinger was brought in to fix things, but the board of directors got uncomfortable with the amount of money required to fix the problem.

It's not really ambiguous at all. Tim Cook for all his faults did not torpedo the cash cow that is called Apple. For almost half a decade the market cap of AirPods alone exceeded Tesla.