I always get to see the trailers before the movie with the exception of limited release films a la Whiplash and Birdman. Usually, if a movie has critical acclaim and it interests me, I'll go out of my way to see such films. This doesn't mean I'll always take away from them, but it helps to expand ones horizons.
I think there's a misconception involved with film criticism that, listening to or reading it keeps you from being able to form your own thoughts and views as to whether or not you like a film or not. On the contrary, I believe that you should read criticisms after a movie so you can better learn how to read and react to a film. The more you understand about film and how it works, the easier it becomes to have a greater connection to a fantastic work.
The reason many become critics is to discover and share more of the world through the art of creativity. It's not simply to trash or praise the wit (or lack thereof), structure, or artfulness of a film. Film that presents you with pretty imagery must have a reason for the pretty imagery. The Revenant, as well as it was filmed, for example, arguably likes to show off more than it likes to develop atmosphere. Whereas, say, something like The Witch will slowly grab you and pull you into the world of fear right with its characters - given you meet the film halfway.
Film - no, art - is a wonderful thing that is fully experienced with, well, experience. Critics are just trying to share that experience with the rest of us.