Ever been curious if it's a good idea when movie studios don't show their films to critics before the film opens?

This graph (from Slashfilm) is a good indicator if how these films end up critically and financially. All this comes on the heels of G.I. Joe coming out without being screened for critics, so we shall see how it turns out for that big loud summer movie.
The entire article (complete with more graphs) is available here, and is a good read.
-Thoughts?