Oh, believe me, the grass always looks greener on the other side

I constantly get bashed for daring to support Apple or try to explain what I think what could be the logic behind some of their moves
That is a tricky thing. For example, Snow Leopard is for some reason widely regarded as the 'most stable OS X ever'. However, back than I was using Opera and Thunderbird instead of Safari and Mail. Safari was crashing constantly for me and Mail had major slowdowns and difficulties with supporting gmail. Furthermore, Snow Leopard did not work with my router, forcing me to buy a new one (which was a big deal for me, as I was a student and didn't have much money back then).
All in all, people tend to idealise the past. Nowadays people forget the controversies or known problems with Snow Leopard (like probably the the most dramatic data deletion bugs that an OS X launch ever had on its history). So far, people were complaining about EVERY release. You just can't make everyone happy. I am quite sure that 5 years from now many would remember El Capitan as the golden age of OS X after which everything went sour.
If they introduce touch screen on their laptops, I would be quite disappointed. And sure, I would certainly admit that I was wrong in this regard. However, an LCD touch bar instead of function keys is an amazing idea if done right as it would allow the system to give additional information to the user and adapt to the current state of the system. Replacing function keys by OLED keys ≠ touch screen. Furthermore, we already have a touchscreen with advanced capabilities (up to handwriting recognition) — its the trackpad.
Of course that is what people desire! After all, they want to have a working OS. I do not understand why stability should be equated with stagnation though. We can have both stability and new features. And as I said before, full focus on stability meaning freezing the OS and its features on a specific level. This might be relevant for a server OS, but certainly a non-goal for an innovative company such as Apple. If Apple were conservative in this regards, they wouldn't be Apple and out likely there would be no Macs, because what would the point be in having a Mac over the more affordable Windows? As to your remark 'make a stable OS first and then add features': a) any change is a potential source of instability b) OS X is a quite stable OS already, given how extremely complex it is c) Apple is investing a lot of R&D into stability (e.g. Swift, app-level virtualisation etc.)
Don't get me wrong though, I absolutely agree with you that Apple should invest more resources in the low-level OS development and maintenance. There are some very annoying bugs (like the freezing bug) that have existed in multiple versions of OS X and are not fixed yet. I certainly agree that new features should NOT be introduced at the expense of stability (I don't see any evidence that that is what Apple is doing that though).
And besides, here the story is even more complicated. Remember Vista? Oh, how people howled about how bad of an OS it is. In fact, much of that bad feeling came from the fact that Vista
was designed to increase stability. Microsoft finally decided to enforce things like access permissions and the like (what OS X has been doing since forever). Which meant that most Windows software just stopped working, as the programmers were used to basically s**t everywhere in the system they felt like doing (I am guilty of the same crime). Badly designed drivers — which were the most of them — had the same problem. By the time Windows 7 was released most of the software developers have caught up — and of course Windows 7 was suddenly a 'good' OS.
I don't think that the users who report and discuss problems on discussion sites represent the majority in any form or way. It is obvious that only users who have problems will report problems. But what about all the users who don't have any problems? They are essentially an invisible dark matter in this aspect. Polls like 'did you have issues with 10.11' won't help either, because people who have problems are more likely to vote. You can only check this by doing a representative sample and interviewing people. If problems would be massively widespread, the reaction would be MUCH more visible. I must have around two dozen machines running 10.11 right now, and only one user has complained about decreased stability. Sure, there were some initial issues for some setups with the new stricter security settings for OS X (which basically boiled down to third-party apps not respecting the design guidelines), but that was quickly fixed.
As to the low rating on the app store... the distribution is bimodal, which basically tells us that people who have an issue go there and give it 1 star. Not much more can be inferred from that, certainly not any representative idea about how satisfied people are with the software. I find it much more telling that the adoption rate for new versions of OS X are so extremely high. El Capitan is currently installed on around 50% of all Macs. Surely if half of the user base had serious stability issues that number would be much lower.