This sentiment seems fairly common in various comment threads I've seen. The dancing aspect seems to evoke in some people... discomfort or something hard to pin down, and I wonder why. At the end of the day, electricity is still electricity whether it's being delivered through power lines or pulsed through fiber optics or pulled and stored in someone as static electricity as they dance. Most science fiction dealing with time travel or teleportation seems to rely on a machine or a suit or a phone booth or some mysterious futuristic means of energy. Yet tribal dancing is one of the oldest human traditions of energy expenditure, done ritualistically. It doesn't seem entirely outlandish to me that a certain configuration of certain energy expenditures by humans could create some sort of ripple or warp or whatever in time space.
I think part of the problem is that it signified a shift in genre for a lot of people. You start out with a mad scientist who is doing experiments trying to understand death and the story of the girl who escaped his grasps. The dancing scene transitioned the show to be about someone who can heal people with hand gestures. I enjoyed the twists, but I can certainly imagine someone viewing it as going from (somewhat) hard sci-fi to being about magic and that change turning them off the show. The fact that the actual dancing look ridiculous also probably didn't help.
I find a lot of shows are trying to check both the "belief in belief" box and the "sciency" box at the same time, and it does a disservice to both. The OA on Netflix and The Oasis on Amazon are just two examples.
But the show doesn't give the viewer any solid evidence that the dancing did anything really. We have to trust the characters, and they could be unreliable narrators. The main characters in the show could be schizophrenic.
It's like a homeless man being in a cardboard box and duct tape suit screaming about his mech suit. You just feel bad for him.
It felt like a cheap attempt at being mysterious or deep. If you look at the people behind the show, it's seems like this is part for the course with their work.
I was also somewhat irritated by that. I still enjoyed the rest, though. The whole dancing thing just made me realize for the first time that the show won't keep all it's promises (for instance, the scene when OA bites the dog and it becomes "tame" had a lot of mystery surrounding it - but that's never resolved. And can never properly be explained by dancing ;-) ).