Yes, let's take a look at Ebert's star ratings for the movies selected that he reviewed.
The Wizard of Oz * * * *
American Graffiti * * * *
The Birdcage * * *
This is Spinal Tap * * * *
Field of Dreams * * * *
O Brother, Where Art Though * * 1/2
Top Gun * * 1/2
Ghostbusters * * * 1/2
Note that other than Top Gun, which I'll give you, the only movie less than 3 stars is a movie where Ebert's take was quite different than many other critics and audience members.
The only movie he didn't review is 20 Feet from Stardom, which is amazing, was critically acclaimed, and a pleasant surprise as the Oscar winner for Best Documentary.
So please tell us again how the wonderful Mr. Ebert would have dismissed this list of movies.