Excellent question; I have dropped both "Alcatraz" and "Person of Interest" after a couple of episodes because of this problem.

Three hypothesis: a) The procedural formula is easier to pull off successfully with limited writing talent. b) Having a handful of permanent characters and the rest be one-offs is cheaper in terms of casting than a complex plot with many, layered recurring characters. c) We are atypical, and most people prefer the comforting, predictable procedural formula. (In particular, it allows for tuning in and out of a show missing episodes here and there with no great loss.)

To be fair, using information from alternate worlds is an interesting spin on procedural, if you do it right.

Independent of Alejandro1's good suggestions I have a thought about the pacing and lastability of premises for TV shows.

I suspect it would be very difficult for an exploration of just that premise to be stretched out into a full length tv series and would likely be more suited to a standalone novel or movie. Similar for a lot of other tv show premises that are attached to more generic shows.* If the main characters devoted their sole attention to resolving the premise it would be implausible for them not to resolve it within a few episodes, meaning they can't play with it anymore or have to resolve some of the interesting ambiguity of it.

Other examples of the top of my head would be Life on Mars, Tru Calling, contrast to say Primer where the premise is the entirety of the plot, but its over much quicker.

Why they want shows that last a long time rather than one shots probably comes down to the economics of the television industry, which I don't know much about.