> Do you believe in the concept of objectivity? Meaning some movies are Objectively better than others, some Reviews are Objectively better than other?

In this context? Absolutely not. One person's favorite movie is another's least.

> If I bring a bunch of kids and teens to the movie, and at the end they all cant stop talking about how much they loved the rock, should I give an Oscar to Ryan Gosling?

It's OK for a movie to not be an Oscar contender.