I see your point, but there are a lot of exceptions. Again with the MD+ and JVC you'd be comparing a BA driver to a Dynamic driver IEM. They sound different and shine in different ways, anybody could listen to both and hear a difference.
Again, I understand where you're coming from on this point. I have put on headphones and listened to gear after a long hiatus waiting to be wowed and I realize, I'm trying to hear 'something' when it's the same old music! As I've spent more money I hear bigger difference, but my headphones and iems are all below $300.
6xx/600 headphones and these two iems. no rule saying you have to own kilobuck or half a kilobuck headphones. MD+ biggest issue is the cheap ass cable which aint worth $5, the lack of more treble and soundstage, and the low af impedance which forces you to spend more money to run it with something that's not a phone or laptop. On the flip side, once you run them right they don't suffer from BA timbre as much as the Blessing 2 I tried and they are the most comfortable iem I've had.
But yea! No need to buy $1500 iems, you get a lot for your money with stuff at this price point.