It is a pointless break with the past. I have no real issue with breaking from the past if there is a good reason. For example I support PA, and Systemd looks like it will be good (I need to find more rebuttals from upstart devs, though. But either way it is leaving sysvinit behind). But when it gains you nothing...
And you lose things as well.
Network transparency - sure, they say "we'll just layer it on top, it will be easy and work well". But so far it is a no-show. I also haven't seen whether or not it would be possible to do single windows like X, as opposed to full desktop.
Then there is the client-side window decoration thing, which is just stupid.
And the "you have to write a compositor to write a WM" thing seem iffy to me. I am not sure how big a problem this is, but it was not reassuring the way they first talked as if there was no possibility of WMs. Just a misunderstanding, it seems, but the compositor may still be an issue.
And as I said, it breaks with the past - how many wonderful X WMs will not be ported/recreated for Wayland? I don't like it, no sir.
A few times I have wondered if I just am not hearing the wonderful things it will bring instead, but then I have gone looking, and I have not found any truly inspiring essays/discussions about Wayland.