X11 is not really fixable, architecturally. This wasn't some authority saying "X11 is over, stop working on it." It was the X11 developers and DE and WM developers who work directly with the protocol deciding that it's untenable to fix, and something new is actually the right call. That's the important thing that many people are missing: the X11 developers ARE the Wayland developers, and they actually have good reasons.
Nobody is stopping you from pulling together a group and working on all this free software, forging forth on Xorg, and forking or maintaining the DEs to work with X11 as long as you want to maintain it. I think the group of people who wants to do that will be quite small, because I've really only seen the sentiment from people who have never actually hacked on an X11 codebase and worked with the protocols themselves. You can want X11 to stay alive, but you can't really demand the people who don't want to work on it anymore to keep working on it.
Nobody is stopping you from pulling together a group and working on all this free software, forging forth on Xorg, and forking or maintaining the DEs to work with X11 as long as you want to maintain it. I think the group of people who wants to do that will be quite small, because I've really only seen the sentiment from people who have never actually hacked on an X11 codebase and worked with the protocols themselves. You can want X11 to stay alive, but you can't really demand the people who don't want to work on it anymore to keep working on it.