OS X user since 10.3, and while I share the opinion that their software quality has gone downhill, they've always done bundled app and OS upgrades: they co-develop major updates to the OS and its SDKs with applications that make use of them. That isn't a major delta from prior releases which held themselves to higher standards.

While holding back app updates to stabilize the early upgrade experience might work, it's also somewhat contradictory to the idea that they upgraded the apps and their features and upgraded the OS as necessary to support the apps and features.