I have had minimal problems with KDE 6 and Wayland, but I dislike the idea that both cannot co-exist. There is no reason to force people to Wayland. There are applications that benefit from Wayland’s tighter security model while there are applications that benefit from X11’s looser security model. If I make an appliance and I want to remotely debug, X11 is great since I can use X11vnc. If I want to run malicious software in a sandbox environment, Wayland is great since it can be properly isolated. They both have their uses. X11 is far more mature too and thus has fewer problems.

That said, I am probably preaching to the choir, as I think we are both moderates as far as the X11 vs Wayland debate is concerned.