The hybrid-graphics support is one of the examples - the technology is quite popular for several years, yet we do not have proper support. And it's not because bad corporations dislike Linux, just because Linux can't simply support these things in easy and cheap to manage way. Yes we have emerging Wayland, but it still lacks hybrid graphics support and is in development for 5 years. Way too long. When to expect it being ready? 2016? 2018? Canonical has plans for 2014.
This is what doesn't make any sense in your argument: you complain that Wayland is taking too long, so you think it's better for Canonical to start from scratch on an entirely new display server? Why? There is simply no way in hell that Canonical is going to be able to get their display server finished faster than Wayland.
Putting extra people and money wouldn't help, because of the lack of the control - fighting with community to add some features and remove other would take too much time and too much effort. For example: Canonical wants to throw away system tray and uses indicators to deal with programs in the background. There will be no such thing as system tray in Mir, because it only complicates the whole. Other distributions want tray, just because of "legacy programs". Conflict of goals.