I agree with most of this. However, to the extent that a few others have painted him as nigh irreplaceable, it feels like your critique might be a little hypercritical.
For his position, I actually think BHH is actually a pretty good passer, and his jumper inside 15' is also certainly more than adequate.
That said, I agree with the rest. He has no post moves. He's strong, but doesn't implement strength as part of his arsenal because he wants to be a finesse player. He's likely been allowed by previous coaches to float around the perimeter masquerading as a guard and never made it a point to develop his inside game, which was exposed at the college level. Years of coddling and placating have done him no good, and Barnes seems to have communicated that the buck stops with him.
It's really surprising that a player who has likely never been held accountable would want to play for Barnes. It isn't like his reputation is a secret, and I highly doubt Barnes sold him a bill of goods in an effort to sign him, so the marriage just seemed odd from the start. The divorce, now, shouldn't be much of a surprise. It felt like the light may have come on for BHH at the mid-season point, but that obviously wasn't sustained, unfortunately. To me, the glimpses of his talent and and potential are obvious, but as you said, the drive/motor/desire just doesn't seem to be there.