A dark ride just by default is perceived differently, and I find (at least in the UK) that they maintain queues for many years. Whether that's because they have the allure of no one knowing what to expect and thus not judging the ride as being too tame or too scary which brings in a wider audience, or just the allure of the unexpected in general, or to do with the damn weather, I dunno... But they do get solid queues.
What they don't do particularly well is bring guests to the park in the first place, or they certainly don't do it anything like the scale any outdoors ride you can put on the TV and make to look impressive does anyway. They are hard to advertise. They are experience based entirely, where as a coaster is a very visually aided thing where the way it looks will massively change your experience of it.
They aren't, if you notice, really pushing the fact that this ride is a prototype. Maybe that's because it's not. But if it is, that probably means that it's not a prototype for the sake of it, but just because they wanted something that does something in a very specific way. I don't get the impression a ride type was picked and the rest of the experience was built around it, I get rather the oposite. Which is the way it should be done, and the way I wish more rides were conceived.
I think they probably wanted a new narrative driven dark ride, since it's been 10 years since the successful Hex the other aim is to revitalise interest in Nemesis, which in the public's eye isn't worth shouting about anymore.