I for one am not someone who shits on the ending although it could have been better. I think a larger portion of general audience will accept fantastical elements, especially when introduced early, compared to religious nonsense.

Partly the same reason Battlestar Galacticas ending isn't generally liked. For the majority of GoT I refused to believe the red lady's powers were anything to do with a God and were just random magic powers since in the real world its all just sky fairy bs. Why should I accept this other world fictional or based on ours has real gods