what is arrogant? that some features matter to some users? or that developers that work for free have things that matter to them in trying to develop better code?
It's not bragging - the commenter stated that Wayland has no advantage, which isn't true. It has many features which just are not possible in X. Many of these features are par for the course on Windows and MacOS. They do matter to some people, but not all of course.
No, it definitely does. Features like disparate refresh rates are very difficult to implement in X11 so they weren't. Bear in mind we have exactly one modern X implementation, x.org, and it's very hard to add new features. The codebase is old and complex.
The main strength of Wayland is that it encourages competing implementations. There are many Wayland compositors. That might be interpreted as a downside, but what it allows is innovation and incremental improvement. Something that was just not happening with X.
You could argue that it could have happened with X. What you can't argue is that it did, because it didn't and that's not up for debate. That's just the truth.
And, it doesn't even matter anymore, because x.org isn't being actively developed in any meaningful sense anymore.
No, I don't think this is true and just the usual nonsense used as justification. Some people continue to develop X, so I hope this is sufficient that I can continue to avoid Wayland.