I believe focus groups have a big impact here too. Saw this in some movie and felt that it is really a big thing.

Producers and directors often rely on the masses (represented by focus groups) when making decisions about certain pieces of the film. They have to dumb down some parts or at least make them straightforward to ensure higher ratings by most (or average) viewers.

That said, we’re lucky to have variety humanity didn’t have before and I can’t complain — there’s still tons of gems out there.