The Masters of Luxor was going to be the second story in the first season of Doctor Who. It was deemed too bad to use, and thus contributed to the success of the show. Confused? Read on...
Having written the gripping tale of how some cavemen got fire, Anthony Coburn came up with a script to follow, which would detail the further adventures of the TARDIS crew. The story features an alien city, robots, a super robot called The Perfect One that wants to become human, and attempt to drain the souls from the two women in the TARDIS crew, the creator of the robots hiding in stasis in the wasteland, the Doctor praying... You can see why this didn't get produced, right?
It's a nice example of dated and pulpy sci fi, but also comes with a thread of "science bad, religion good" running through it. Since there was a drive for a serious sci fi series at the time, there wasn't going to be much room for a parable about how scientists are arrogant bastards who will doom us all with their godless ways. "Why are scientists so evil, mummy?" "Well, you see, science just makes people do evil things." Yes, it's that sort of story. Scientists are shockingly evil people if they aren't also religious. But watch out... Science makes you burn holy books! Science makes you experiment on human subjects! Science makes you try to create life!
Instead of this story the production team instead went with a script about hideously mutated survivors of a nuclear war who are confined to their strange city, cannot move under their own power, and are trapped in the tombs that are their travel machines. The title of the story is The Daleks.
It's largely the Daleks themselves that made Doctor Who such a success. The show had originally been allocated thirteen episodes to run as a test. If it hadn't taken off in that time, there might not have been any more Doctor Who. I'm not so sure that The Masters of Luxor would have been quite as effective. I mean... humanoid robots having boring conversations about the nature of humanity, or Daleks shouting at people and waving their paint rollers and sink plungers around while people talk about the nature of humanity? Of course, when the alternative to this one is the genocidal dustbins of Skaro it's really hard to make a fair comparison.
As for Luxor, it used to be available as a script book. I think if the religious aspects were removed and the motivation for the villain tweaked away from the slightly bizarre soul-syphoning plot, it might have been all right... But it's for the best that it was deemed unusable back in the 60's, or Doctor Who might not have lasted as long as it did.