never seen in reruns? I can understand why short-lived shows that lasted 1 season or less aren't but what about other shows For instance TRAPPER JOHN M.D.

Trapper John M.D. has been shown in reruns, but it's been several years since I last saw it. I know one of our local channels ran it late nights.

never seen in reruns? I can understand why short-lived shows that lasted 1 season or less aren't but what about other shows For instance TRAPPER JOHN M.D.

I'll admit that I am just guessing, but I suspect it has something to do with royalties.
I suspect that the networks like to keep their costs down by negotiating favorable licensing agreements, that perhaps not all rights holders are willing to go along with? Some might be more agreeable to "bulk packaging" agreements, than others.

And I've heard of weird conflicts in rights for some shows where the bands who played musical accompaniment hold rights over their contained work separate from and in addition to the tv show. Sometimes they will go to the trouble to edit out these audio clips that secondary rights holders own and replace it with open source audio....but perhaps not all shows have sufficient appeal to be worth that extra effort, so the shows are just left sitting in the vault?

Whenever there is evil, usually you don't have to look very far to find money at the root of it.