The only thing that makes any possible sense here is that CHUCK is a filler until they can get a similar idea up and running.
(programming from the same Genre)
I mean, to say so respectfully, regardless of ratings for CHUCK, someone high enough up must have some faith in the idea that ANY television programming that is all about a guy that is both a store employee and a spy of some sort has (Very?) good validation for good to great ratings.
Why else would the decision to keep CHUCK running be validated?