There’s definitely no shortage of armchair critics, but particularly when it comes to design, some amount of the criticism comes from having tried to engage with open projects to help improve them only to be snubbed, downplayed, ignored, etc. Of course this is a complex issue since these kinds of interactions vary wildly between projects and individuals in those projects, but you can see how that might bring frustration.
Incidentally I think this has also been what’s inspired many of the numerous forks and new projects within the Linux desktop space: people who initially intended to contribute to existing projects find themselves unable to effect substantial or sufficient change, become frustrated, and go start their own thing.
This is definitely a thing, but I hope KDE specifically on average has a rep of being easy to get into and owning our mistakes. At least this is really the culture we try to cultivate broadly.
For example, we also have some devs who proactively read or watch negative reviews and extract the good points into tickets (it's a nice low cost source of one form of user testing), and we've over the last half-decade or so built a strong culture of paying attention to user pain points, change defaults to match expectations, etc.
I know this thread reads pretty negatively, but I can say confidently our userbase has never been happier and the total number of users we serve well has grown significantly. You can even see it in the metrics - our monetary user donations have tripled in the last couple of years.
Incidentally I think this has also been what’s inspired many of the numerous forks and new projects within the Linux desktop space: people who initially intended to contribute to existing projects find themselves unable to effect substantial or sufficient change, become frustrated, and go start their own thing.