I don't see any explanation in your comment of how any of those aspects would be worse.
You say "Apple wouldn't profit much more from the switch" because of the volume discounts they get from Intel, but you don't cite exactly how much of a discount they get, and you still concede that Apple's own ARM chips might have a lower cost.
You say "battery life would go up a bit," and seem to imply that it could be up to 20%, which in my opinion is massive.
And you don't address size.
How then are any of those aspects worse? Even under your own seemingly pessimistic estimates, cost and battery life would improve.
All their old apps now run probably 2 to 10 times slower, until new native binaries arrived. Compare that with the PPC->Intel transition, when old binary apps stayed about the same or maybe got a little faster.
Also, emulating Intel binary apps with the CPU pegged for twice as long nullifies any energy savings, so the battery life in practice gets worse. Even if it is 20% for native binary apps, consumers are going to see "new computer, worse battery life, Og smash!" during the transition.
You're not going to see a 20% gain in battery life for native binaries, though. The only way you'd see that is if the ARM CPU used no energy at all. Extraordinary claims, evidence, and all that.
Is there really any reason to think that an Intel and ARM chip of comparable performance will have significantly different package sizes? Intel has always been the leader in process technology, so it would surprise me if the ARM die were any smaller.
I don't see any explanation in your comment of how any of those aspects would be worse.
You say "Apple wouldn't profit much more from the switch" because of the volume discounts they get from Intel, but you don't cite exactly how much of a discount they get, and you still concede that Apple's own ARM chips might have a lower cost.
You say "battery life would go up a bit," and seem to imply that it could be up to 20%, which in my opinion is massive.
And you don't address size.
How then are any of those aspects worse? Even under your own seemingly pessimistic estimates, cost and battery life would improve.