This argument is actually backwards: one of the goals of the wayland project is to draw development away from X. If wayland didn't exist, people would have worked on X11 a lot more.
It's not an argument in the first place: it's describing the current situation. Wayland does exist, and did draw development away from X.
It's not an argument in the first place: it's describing the current situation. Wayland does exist, and did draw development away from X.