My complaint is that adding another season doesn't enhance a begging-middle-end story arc that's already done, especially when it clearly was tacked on and not part of the original story.
What I'd prefer? Give the creator a blank slate and let them make another amazing story, rather than saying "this Ducati is great–keep adding wheels!"
Check out the notes here: https://en.wikipedia.org/wiki/The_OA#Production which make clear that the season 1 story was a cohesive, beginning to end story that the creators refined over a series of years (and it shows). Then "hey lets add a season 2."
I guess it was before things like "Melancholia" and "Interstellar".
This guys is a genius.
These three I've seen personally are all good and have a lot of overlapping themes and premises, like mysterious charismatic figures in a slightly off kilter, ambiguously fantastical world convincing people to believe and follow them and their reality.
It's almost comforting to know that The OA is a third or fourth shot at that kind of premise by Brit and her collaborators. Maybe that's why it felt so beautiful and out of nowhere and perfectly formed.