Are you trying to imply that subbing WHM was some crazy, unreasonable sacrifice for 75BLM? In the LV75 era, WHM was literally
the most popular SJ for BLM in the game (by nearly a five-to-one margin!), and the 2nd most popular job combo in the entire game. Please do not try to spin BLM/WHM as some sort of rare, unacceptable compromise. (And if you're thinking of making an impassioned plea for the incredible superiority of BLM/RDM over BLM/WHM, don't bother; you can literally replace my previous citations of 75BLM/WHM with 75BLM/RDM and everything I said is precisely as true.)
That being said, you're confusing the issue; the question is not whether 75BLM could reasonably sub WHM (note: they could) or whether THM can acceptably equip Cure, but their effectiveness as a healer when making that choice. And the plain and simple fact is that THM equipping Cure (compared to another melee) is the functional equivalent of BLM/WHM (compared to melee/WHM).
Maybe next, SE can remove all tanking abilities from MRD and PGL (in the name of "class identity"), so you can complain that there should be more tanking classes?
You're asking for an enfeebling class to be created when one
already exists right now and is being blown up as a direct result of your cries for class identity. This makes no sense.