As I mentioned above, I don't feel strongly about Bluesky winning, I just don't like misinformation. (I also have other things I care about more that take up what little free time I have for tech stuff already, so I'm not going to undertake something major just to prove a point.) If there's really a fundamental problem with AT Proto and how it can be used, Doctorow's post should have made that explicit.
I did find a (more recent) post that goes into detail about what's lacking, and I've edited my original post accordingly.
There's documentation on how to set up your own server for each of the components involved, and there are example servers running. It will take time for an organization to decide to run another major instance, though.
See also https://lemmy.world/comment/13555889