I don't know. I consider macOS an operating system. It's sole purpose is to make the hardware work and run my apps.
It has done so, without fault, for me, since I switched from Windows in 2008. I don't know where the hate comes from, maybe it's Liquid Glass. Maybe not. Maybe macOS has looked better in the past, maybe not. Maybe the corners were a different radius. Maybe not.
In the end it does what it's supposed to do.
Pretty much. They way I think of it, I don't actively look at the OK, I thought through to OS to what I'm actually doing. What I don't want is the OS to get in the way of what I'm doing.
System 7m OSX, MacOS etc has generally been much better at this, getting out of the way, than Windows.
Some of the hate is just to have something to say, the internet needs noise, and hate and grumbling is a way to fill the noise when there's no actual content.
I do think the yearly macOS version update does exasperate this, though, mainly because it isn't really a new version every year, it's more like a new macOS version every 2-4 years, but Apple wants to present a regular, yearly cycle.
So, what I mean is that, say Big Sur and Monterey were really the some version of macOS, but Big Sur was an early version. Going back through the years, you can see the same pattern. MacOS27 is going to be the "more finished" version of what MacOS26 was going for.
So I think the complaints come from people expecting that early iterations of a new cycle of macOS should be perfect and complete with every version, but software just doesn't work like that. So people complain about the early versions, and when that cycle is in it's final version, where everything is fully realised, people;s head explode the next year because the cycle starts again.
Thinking about an OS as a finished product is always going to be problematic, as this doesn't fit with the reality.
Personally, I'd be very happy if Apple went down the "Leopard / Snow Leopard road again, where one big yearly update is about new features and UI changes, and the next is only "under the hood" changes, but theindstry doesn't seem to work like this anymore. New releases every year, irrespective of whether they are ready to be released or not.
People want "new and innovative" every year, and they also want "perfectly executed". But I don't think it's possible to do that on a yearly release cycle.
The one thing I note on this site (and others), is that "the community" often has wildly unrealistic expectations.