Hope HM isn't cheap. Having said that, we're only playing HM to get better/higher gear to do better in the HM raid as we're high enough now already to do everything else in the game. The difference between now and back when CE and VoG were alive is the gear in those raids were worth chasing.
There's nothing (that we know of so far) that stands out in the raid in terms of gear. Nothing worth grinding over and over for. Sure, all 320 stuff would be cool, but it's still only going to help you in the HM raid. Nothing you can get from there that you think "wow this will make everything else in Destiny so much better/easier" like with fatebringer, black hammer, found verdict, etc.
We'll see. But if HM is just cheap mechanics and over-leveled enemies, I don't really see the point other than just wanting to tackle the most difficult content out there just because.