It is not fair to single out Apple - all the software has gone downhill in the past couple of years - browsers, websites, apps, appliances, virtually everything. My suspicion is that it's the proliferation of new ways of doing things - new languages, no-sql/key-value db's, new hosting platforms such as AWS, docker, big data stuff like hadoop, storm and spark, all kinds of embedded software (tv's, cars), etc - we've g…
You can't be fast moving and have high quality. Software is like any other trade: polish takes time and you need to stop to polish things. This thread has a lot of people praising Snow Leopard. Frankly, the difference between Leopard and SL aren't the high, but that's two years of development at Apple to polish things up. Apple had a rare slow moving period to clean things up.
I suspect the mobile/cloud/whatever revolution is only recently slowing down and we'll be entering a polish period again soon. Then we'll be entering a complexity building period sometime after. Its a cycle that keeps repeating itself.