>Is that 'unfairly discriminating against a certain demographic'?

I suspect it gets a free pass because the demographic being discriminated against is better off (eg. adults who tend to have more disposable income). If it were the other way around (eg. software companies charging elderly people more because they don't know any better), there's going to be more backlash.

It's not that they're better-off, but rather that the movie theater discovered that a movie the child wants to see often forces the parents with them. By discounting the child, they increased the sale of at least 1 ticket for the parent, and therefore, they make more money. If the child wasn't discounted, the parent might choose an alternative source of entertainment (because face it, adults tend not to want to watch children movies) and the theater lose out on that adult ticket!

this is why you don't see a discount for couples usually - coz they were going to pay even without the discount.

OK, pretend that I said this instead:

"Most people are fine with movie theatres charging 65+ SENIORS less than they charge adults."