I don't know that they're "not that great" or a "huge-miss." They opened at a traditionally low time when most people can't/won't take a Disney trip, and they didn't open the whole land, and then they had a hurricane. Also, they originally announced a "late fall" opening, and people who wanted to go for the GE opening probably made plans to go later.
I think the other thing is WDW bet on the clamor being so great that they could jack up prices - significantly - on just about everything. But people balked at the prices. I really wonder what the reception would have been if Disney hadn't pushed the envelope with costs.
On many threads we see someone complaining about prices, and other people chiming in, saying Disney can charge whatever they want and someone will pay it. That if the original poster stops going, there will just be 10 other people there to replace him/her. Except, that doesn't seem to be the case at the moment.
Speaking for myself, I had planned to buy APs this year for myself and my daughter. She's 4, and this is the last year I can take her without regard to school calendar. My original plan was go in Sept when airfare and crowds are low-ish, and then hop down a couple more times for a few days when I can manage the time off - maybe with nothing more than a backpack on a cheap flight on Spirit or Frontier. And then Disney raised the AP pricing by $200, which would be an extra $400 for us both. And Disney started raising room prices, and food prices. And even with the price increases, Disney is cutting live entertainment, which is what, to me, makes Disney a destination that my local Six Flags can never match. After thinking about it, I decided the value just isn't there, even though we can afford it. DD and I will take one trip this year, and that will be it. Not sure when we'll be back.
So, while I agree there will not be more EEMH because the demand isn't there, I wonder how much of the mismatch between expectation and reality is a commentary on the quality of Galaxy's Edge, and how much is the result of Disney's choices surrounding the opening.