As a reader - my personal preference is for stories that don't touch on things I can read about in the Huffington Post/New York Times/The Daily Beast.
When I read about an idealized future, I enjoy seeing the unity of races and species working together against common threats not policing themselves, or looking to root out corruption... When corruption of that type is fictionalized, it is like a easily removed cancer. The reader or viewer can be reassured that everything is all right, and will be all right in the idealized future.
But don't stories like that just re-enforce the problem? If you retreat into the fantasy that there can be a society in which you don't have to be on guard for that kind of corruption, isn't that just another way of avoiding accepting the fact that the problem always recurs, no matter what, and must always be fought against?
I think the most Star Trek-ianly inspirational episodes are the ones that acknowledge that these problems will always recur but insist that they can be fought.