I fully agree. I jumped on the Mac and OS X bandwagon in 2007. The first few releases of Leopard (10.5) were quite hellish, because I was constantly having Wifi problems. My HP Laserjet didn't work until 10.5.2 (in 10.5.0 and 10.5.1 it would just print a few pages and get stuck). Snow Leopard was a smoother ride, but only after a couple of dot releases.

I think there was a low point around Lion and Mountain Lion (lots of new features, but they were not polished enough). But since Mavericks it's been smooth sailing for me.

People also seem to have overly romantic recollections of past Apple software. Sure, Aperture and iPhoto were killed in favor of Photos. But Aperture was crap. Version 2 was still acceptable, but 3.x had constant hangs and slowness. And they were always trailing behind badly with RAW support. As many people, I have bought Aperture 2 & 3 and switch to LightRoom pretty soon after because of Aperture's lack of polish. A while ago I tried the new Photos. And although it does not have all of Aperture's features, it's a far better application in terms of speed and user experience.

tl;dr: I don't see this drop in quality.

Of course, App Store and iTunes need to be burned down to the ground and rewritten from scratch.