"Abandoning" standards was done because X11 was the standard and it was too complicated for even the X11 maintainers to want to deal with. Wayland, for better or worse, splits up a lot of responsibilities and even offloads some to the app developer...
Linux has nothing to do with cooperation. It's a survival of the fittest scenario. People make things, then other people either adopt them or don't.
Gnome has a working screen reader on Wayland. They have APIs for accessibility on Gnome. Should RH/Gnome be responsible for all the Wayland compositors and DEs that haven't implemented it? Should they be responsible for a proprietary app that chooses not to work with what they're given?
Again, X11 exists, works, and no one is forcing it to go away. Devs can ignore Gnome/Red Hat things and do whatever they want. Or they can make their own thing work. Blaming others for not doing work they're too lazy to do is wild...