Back when I worked in a theatre in NJ, we actually did what we could to ensure everyone had an enjoyable movie going experience.
The standing policy was "No Children Under 6 Admitted into PG13 or R Rated Films after 6pm". Ushers would actually do theatre checks every 15-20 minutes into the feature. Projectionists would actually ensure that everything is framed up when the previews start and check that the feature is in frame when it starts.
Since coming to LA, I haven't seen anything like this anywhere with the exception of the No Children Under 6 policy at a few theatres.
The theatre checks were done to ensure that picture and sound looks good, as well as ensure proper audience behavior. When was the last time you saw an usher tell people to be quiet? Or the last time someone told someone to stop texting?
When a feature starts, it's the projectionists job to make sure everything is properly framed. If the previews are off by a sprocket, they need to check that the feature is in frame when it starts. I've never seen this done. When I was a projectionist, I would make sure the trailers are in frame before walking away to start the next film. When walking by I'd check to make sure the feature is in frame. Countless times from the Arclight to Burbank, I have not seen anyone make a framing adjustment during the trailers which led to the film being out of frame. It's not my job to get up and walk all the way back to the lobby to ask some one to fix the framing. Just because the picture is on the screen and no frame lines are visible doesn't mean the picture is centered. The New Beverly is the only theatre I know of that corrects the framing as the feature goes. They have older prints and are always at the ready to fix any problems.
Another thing that really pisses me off is Pacific's policy, which includes the Arclight, to only issue readmissions in lieu of refunds. I had a friend who was trying to make a show, Defiance, but finally texted me that they won't make it in time. The feature had just started. When I told them that they said if you had come out they would have refunded it. I said you're telling me I'd have to miss part of the movie to take care of this. It's there policy. Incidentally, the theatre was the Grove and I still have that pass. I haven't been back there in over a year, nothing there to see that I can't see elsewhere.
The movies are what people are paying for, if you're gonna half-ass when presenting them they should just assume watch them in the comfort of they're own home.