I've really been noticing how Apple software quality has been on a slow decline since Snow Leopard. I look at some of their older source code and it's a joy to read!
Nowadays, my daily travails with restarting Xcode multiple times a day to work around bugs (package blahblah is not available) have really worn thin (I mean, Xcode has always had problems, but not THIS bad). Add to that the fact that the "system data" on my mbp now takes up 80% of the space on my SSD (800GB of system data! Even after manually deleting caches and derived data)...
It's like they don't even care about code craftsmanship anymore. And yet their culture of not putting in useful debug messages (because "it just works") persists.
My latest and greatest headache? Some parts of AppKit now directly call [NSApplication _crashOnException:] regardless of the "NSApplicationCrashOnExceptions" setting, and WITHOUT even calling [NSApplication reportException:]. So now you lose the exception entirely and good luck figuring out what caused the crash. Ugh...