If you are able to type intelligently on a computer, as seems to be the case, you are not “100% disabled” for federal work purposes. The system does not work and as you point out, is arbitrary. I think it needs periodic reviews with cancellations when it appears that the rules are not being followed.
Becoming disabled did not render me stupid.
It did, however, render me incapable of holding down a job. My impairment cycles from moderate to severe. My treatment renders me as disabled as much as the original disability.