A. Free software also means that you are free to ignore the community. As long as Canonical continues to release their software under a free license and they coordinate compatible APIs with the rest of the ecosystem, I think its good on them that their are doing what they think best.
B. Please read the Mir Ubuntu wiki page before you jump to conclusions about who’s FUDing who. I don’t agree with all of their design decisions, but clearly their design requirements (specifically the shell “security” requirements) prevent them from using the Wayland protocol. As for using the Weston software stack – there are real concerns about their HAL APIs not working with the Android driver model – which is the current main target for Mir.
C. You can say that it is best if Canonical would have worked with the Wayland project to integrate all their requirements into the Wayland system, but as can be seen by the current shit storm in the freedesktop community, people are not really open to talk about extending the requirements of their “spare time” community projects to support what they perceive as a lot of work for a commercial-only software vendor. Canonical has seen this in the past several times.

As a software developer who likes and believes in free software but was also several times in the unenviable position of retrofitting the requirements of a commercial product onto a free software community project, I think their current behavior is the best that they can do.

I don’t expect free software community projects to bend over backwards to facilitate this or that commercial product, but the current position of said free software community project makers and shakers is that the commercial company should bend over backwards to get inline with the requirements of the free software project. Canonical is a commercial company that needs to put out a product that they can support, and if they can’t do it by being fully compatible with an existing project, then they can either maintain their own set of incompatible patches (as RedHat has done many times, and no one likes that), fork the project (which no one likes that either) or design their own thing from scratch – and as long as that is also free software, that seems to be the best approach.