there used to be 'crying rooms' in some Mom & Pop theatres in the town where I grew up. this was a seperate room seating perhaps 30--remember this was in the pre-multilple screens era--It had 2 doors & a glass wall & soundproofing.
I would not suffer these inconsiderate parents in silence, a manager must be called & the offenders ejected, just like OP noted. Of course, this means someone needs to sacrifice seeing what may be an important part of the movie, which is a real kicker
We couldn't afford babysitters & did not go to a movie theatre for 6 years.
We saw GOF just yesterday & there were indeed small children there & the poor things were crying during various parts of the movie
My most memorable incident was when Jaws came out. I sat in front of a couple that brought in their child, who looked to be about 7 years old. He was just freaking! If I weren't a young teen I would've said something (I did make a few choice comments). The parents kept telling him,"it's just fake stop crying!" I have always felt people like that should be charged with child cruelty
When DS was 3--yes 3--I had to nix playdates with one friend because this family let their kids, ages 3, 6 & 10 watch slasher, R-rated videos. The parents were both college 'educated' & saw absolutely nothing wrong with letting one & all watch the Friday the 13th movies, Freddy etc. what a couple of pips!
Jean