Why, what's so horrible about it? Need more space? The guy says "no" with such emphasis as if he's asked to sign the devil's contract.It would always have been difficult to get wayland into main as a build dep of GTK, but it really won't be possible to have GTK+ depending on wayland.
Canonical was in favor of Wayland in 2010 but now they won't even commit to putting a wayland related flag into the compilation process, not to mention significant contribution to Wayland like patches or so. Making their iso grow from like 780 to 785MB is way over the top?