The original subject here is should Williams be criticized if he doesn't play well. and his reasonable expectations.
You take Williams if you feel that it is going to improve the QB play significantly. If it doesn't, then criticizing him is fair game.
If Williams plays worse, you've given up what you could have gotten for trading out of the spot and using the pick on, say MHj, and still had Fields.
If you draft Williams, he had better be an improvement on Fields. that is not an unreasonable expectation.