Quote from bidask:
the answer to this Monty Hall's paradox is absolutely correct but it's another one of those academic exercises that rely on an academic assumption. the assumption is that you get to travel back in time and choose again.
so while the answer is 100% correct, the question is academic.
most people who have not read a lot of textbooks have a difficult time thinking from a textbook point of view. most people who are only reading textbooks have a difficult time accepting why his thinking, although 100% correct, isn't applicable in the real world.