> Somebody who worked on Snow Leopard has already disagreed with you here about those things:

It's instructive to read the entire thread, not just the few sentences you quoted. For example, that person later admits, "So yeah, if you are comparing the most stable polished/fixed/stagnant last major version with the brand new 1.0 major version branch, the newer major is going to be buggier. That would be the case with every y.0 vs x.8."

> I don’t think the schedule matters. They just over-commit every time.

That's a distinction without a difference. Apple has committed to releasing major OS updates every year on schedule. That's a recipe for over-committment, because they need to produce enough changes to market it as a major release.

The "no new features" gimmick of Snow Leopard was a marketing lie but was also unique. It's a gimmick that Apple pulled only once, and it couldn't be repeated frequently by Apple without making a mockery of the whole annual schedule. Maybe they could do it a second time now, but in general the annual schedule is still a major problem for a number of reasons.

It should also be noted that Snow Leopard itself took 2 years to produce after Leopard.