Films like this show exactly the difference between foreign filmmaking and American filmmaking...

Yes.

American mainstream audiences 'just want to be entertained' and then they want to go away from a movie feeling that everything is alright again with the world. They resist ambiguity. They don't want complexity or anything particularly challenging. They're not terribly keen on having to interpret things for themselves. (Not that they can't, of course, they just don't think they should have to.)

And they don't take too kindly to downbeat endings.

I suppose it all goes back to the 'golden age' of Hollywood and its escapist fantasies and factory-style mass entertainment filmmaking. And the production code. All of that has just built in certain traditions and cultural expectations of films that other nations don't really share -- continuing to have smaller budgets that allow filmmaking to be treated more like an art than a commodity.

But, of course, it's worth pointing out that, A) the USA is one of the largest markets for international cinema in the world, so this certainly doesn't apply to all American audiences by any stretch of the imagination, and that B) American mainstream films are popular throughout most of the globe, so it's not as though those of us in different nations firmly reject that stuff.

But you're absolutely right that this is the tendency... although, of course, with American indie films and things with smaller budgets it's far less the tendency because they can afford to appeal only to a niche audience, and that part of the US film industry has more in common with filmmaking elsewhere in the world.