It looks to me like there are quite a few more basic features fundamentally incompatible with Wayland's architecture than X's. Maybe X has issues but Wayland is still a regression.
People have different requirements and I heard tons of stories of "this doesn't work, that doesn't work".
It's been slowly improving, but many people also just got burnt because of early hype. I don't remember any specific wayland problem in my personal recent history, but it took years to get there.
It's very common for developers to want to toss everything out and rewrite even to the detriment of the product, business or users. It's also very common for the rewrite to go wrong and end up worse than an incremental improvement path would have been. It's so common it's got a name: Second System Syndrome.
Is Wayland the result of SSS? I don't use it, but it sounds like maybe it is. If it is then "the X developers said it's cool" isn't a very compelling answer. In commercial organizations developers are routinely blocked from doing pointless rewrites or gigantic refactors because a certain type of developer will happily screw everything up chasing utopian dreams of a tech debt free platform whilst the userbase rots on the vine. And very often, there were better and less disruptive ways to get to the desired destination.