Why do people bring babies to the movies?

I was just watching the new Transformers movie today at the theatre,
and there was this baby crying throughout the ENTIRE movie. By the
end, I really just wanted to tell the parent to shut their baby up.
Not to criticize the parents or anything, but do they SERIOUSLY think
a 1 month old baby is going to enjoy Transformers, or even stop crying
long enough to try and watch?