Seriously?
1) GPU optimization in OS X is still abysmal compared to Windows and Linux and Apple is very slow in adopting current technologies
2) native video codec support is completely broken as of Mavericks, making Quicktime almost useless and severely handicapping Quick Look
3) multi monitor support may have improved in Mavericks, but it's still ridiculous and very unpredictable. Say you have an iTunes window on monitor #2 and have had it there for several days now. You go to iTunes -> Preferences and it opens in... monitor #1. Even though you never had any iTunes window in monitor #1 since the app was launched.
and that's just off the top of my head - all very obvious stuff that is never going to get fixed in such a tight release schedule.
1) OS X makes better use of hardware than Windows does. That is fact. So while for gaming (this isn't all a GPU is used for) it is subpar, for everything else, it is not. I run Adobe CS on both Mac and PC. I routinely get better overall performance on Macs with Intel graphics while PCs with low-end discrete just chockes up and lags.
2) QuickTime works fine on my Macs. Quick Look does too. I also have VLC installed and it works fine with Quick Look. Please be specific. I always do clean installs versus upgrade which may or may not make a difference.
3) That has never happened to me. The only way to open preferences for any program is to have that program be in the foreground. If iTunes is in the foreground, you're telling me preferences would open in monitor #1? Instead of the foreground which is monitor #2? I have triple monitors. While multi-monitor support was kind of broken (only for fullscreen apps) in past OS X versions, it has been fixed as of Mavericks. Everything is straight forward.
Also, these are bug fixes. My OP said that the fundamental parts of OSes are pretty much mature. There will always be obscure bugs. No software exists that has zero bugs. But some software, like word processors or spreadsheets are pretty much mature. There isn't much of a difference between the last few versions in terms of function. The UI may be difference, cloud integration may be added/improved and such.
You make a good point. However I still do believe that features such as facebook, twitter integration could have been handled via an update. Annual updates such as done by apple are entirely their choice, personally I would be ok with a longer development cycle. The problem with fast iterations is that it can break certain software/ apps requiring developers to issue frequent updates. I would much prefer that apple labelled such updates as feature packs (i.e. facebook integration, notification center etc.) but its not the way apple doe s things.
I agree. They should even be optional. I personally don't use any of those services so it's just wasted space for me. But then it would be confusing to the end user, they would have to download it and keep track of piece of software. It's better (overall) to make just one version with zero add-ons. OS X Server breaks this rule but due to the nature of it, it's made for more advanced users anyway.
Fast iterations breaking apps is not that bad anymore. Take iOS for example. Most apps on iOS 7 run fine on iOS 8. Sure, there may be performance improvements, new APIs and features to take advantage of and so forth, but the app works in its original form. I don't think OS X apps break from version to version anymore. Majority of apps work fine. Some have some slight issues. But for the most part, it's compatible and will run. But there are new APIs and features of the new OS X version to take advantage of. Or in this case, a brand new UI look.