AMC Theatres review: outside drink

I'm an A list member. I attend movies at least twice a month with my grandchildren. I always take my hydro flask water bottle inside and fill it at the water fountain. No one has ever said anything about this. I mean I already spend plenty of money on concessions so why would they? Well, tonight one of the little boys that clean up said I could not take it in, I explained that I always bring it in and fill it with water at the fountain. He said I would have to take it to my car and it was pouring down rain. I asked to speak with the manager. The manager advised this was the rule and asked if I would put it in my purse, I advised that it would not fit or I would gladly do so even though it made no sense. So, he gave me a cup to pour the water out of my water bottle in to and I had to take my water bottle to the car. I'm sorry but I do not see the logic in this at all.