I think QM is deliberately designed as "play the hero you want" compared to HL's "play the hero your team needs".
I suppose they could make an unranked version of HL though.
I don't know why some people think HL is the Promised Land.
My last 3 HL games were full of assholes, DCs and complete incompetents that picked shit heroes and played them badly. Lost a bunch of ranks, got pissed off and went back to QM.