Why do we, the movie-watching public, care about the Oscars? Because oh, we do care. A lot.
We argue about victors of the past. ("Dances with Wolves" over "Goodfellas"? What an injustice!) We root for our favorite actors. (This is the year Meryl Streep won't be denied!) We participate in various Oscar pools trying to select movies which, for the most part (let's be honest) we haven't watched.
We understand why someone like producer Harvey Weinstein, co-founder of Miramax and head of Weinstein Company, cares. Movies are his job, his livelihood. It's what he is known for: non-stop campaigning to get Oscars for his movies. That, and for being angry, aggressive, and just plain insufferable. And those are his good qualities.
We understand why actors care. And directors, and costume designers, and everyone involved on the movie set. But us? As much as we love "Goodfellas", we are not losing sleep over its loss. We are no better off if Streep wins. And that Oscar pool? Well, there is always next year.
For when next year comes, all reason will go out of the window and we'll care about the Oscars.
(Editor's update, October 5, 2017: Awful. Disgusting. "Sadly, a Jew" doesn't do him justice.)