Without any inside knowledge--and I'd have to revisit a piece I wrote at the time during my prior analyst stint--it always felt like a bit of a sideline/experiment. There were a lot of dynamics going on at the time. Linux was really exploding (and improving). There was a lot of consumerization (especially on mobile) happening within enterprise IT; Apple didn't need to become an enterprise IT company to effectively reap a lot of the benefits both directly and indirectly. Servers were increasingly commoditizing onto dual socket x86 (with some outliers).