Why does AMBIGUITY bother people so much?

I guess I wouldn't want EVERY movie to be like this, but I actually like movies to be ambiguous, or open to more than one interpretation. It seems to infuriate some people though that everything isn't spelled out for them. OR they become convinced that there is exactly ONE interpretation when it's obvious that's not the case, and try to explain it to everybody. I'm not necessarily saying they're wrong, but maybe there is a reason the filmmaker intentionally left everything so open.

Ambiguity is actually the REAL way of the world. The most powerful things in life--like death--are a completely unresolvable mystery. People can't deal with that though so they either tell themselves childish, self-serving religious fairy tales (that seem to involve them personally getting on Jesus' guest list), or they resort to totally rational reductionist atheism. I wish more people could accept MYSTERY and trust that things are just far greater than we are capable of understanding. There is actually solace in that.

This is just a very beautiful movie. It reminds me of the famous line from John Keats that "Truth is beauty and beauty truth. That is all you know on earth and all you need to know".