Sounds like a bug in your local theater's sound setup. The local theaters here seem to have it set up about right: loud when it should sound loud, quiet when it should sound quiet, and never painful.
I thought so too. In fact, I complained multiple times at one movie. They said they have no control over it, and couldn't turn it down if they wanted to. I'm not sure I believe it; _someone_ must be able to turn it down, but I may believe that the average employee on a random Saturday may not be able to.