This is what could have been: In the AMC version of Roadside Picnic you would have followed a Stalker named Red. He is a doctor and has to explore the exclusion zones in order to find out what those Aliens were.
But others are there to satisfy their greed and to find the extremely valuable artifacts which are to be found within the restricted areas.
The show probably would have felt very different from the source material. It was set in the modern-day USA and instead of the post-soviet Russia. The show wanted to stick closer to the original book than the video games. So no Chernobyl and no nuclear accident. Only Aliens who fled earth and left us some precious cargo! But as mentioned, set in the US.
Why The STALKER TV-Show Was Never Made
That went wrong: The pilot was the only episode ever made of Roadside Picnic. People loved the first episode but the people in response did not agree with the audience. Today you can not watch the pilot episode anymore, at least not legally.
The cast of Roadside Picnic was quite unknown but experienced. So the question remains why Roadside Picnic was shot and shown.
Some people believe the theory that the production value was simply to low. But there is no real evidence for that. You could believe this if you watch some shots from the pilot. The thing is that a pilot is never made in the same quality as the real show and mostly does not even appear the main first season.
No one knows for sure: In the end, no one can tell why the STALKER tv-show got canceled. We can only hope that someday someone decides to try this whole Roadside Picnic thing again and succeeds.
Until this happens we will patiently wait for S.T.A.L.K.E.R. 2 or play the DayZ S.T.A.L.K.E.R.-Mod!