He could simply say “it’s not a big part of my offense, or it doesn’t fit what I feel our strengths as a unit are (or any other multitude of reasons).”
And he could say that and we would still have no idea what he thinks of the QB. But we do know what he thinks by his actions: needs "live experience" when down 41-10, won't throw slants, rare play action (which is really weird but there was to be a reason), not rolling him out to try and avoid rush (again, befuddling, but there has to be a reason), not throwing to the RBs (again...)... they don't seem to trust him