Everyone has their own opinions! There are obviously a good chunk of people who really like Oz'Iris. There's a difference between "a bad coaster" and "a coaster that you don't like". The big thing about Oz'Iris is that it was really, really hyped (R.D. keeps calling it Montdeux, comparative to Montu), so you'd expect that it's a fantastic ride that everyone will like. That's very, very rarely the case! There are always people who will think it's "just okay" or "not good".
Examples - the Coney Island Cyclone is probably the worst ride I've ever ridden, but that doesn't mean I don't like it. On the other hand, there are a lot of people who really enjoy the Hersheypark Storm Runner, but I don't like it because it's so short.
Like Eric said, the overall opinion on the park was that it was a great place to stop, so that certainly won't stop me from wanting to go there.