So before we get into the big ideas in this episode (about which, in the good old bad old days of the Internet, essays were written. Long ones), let's talk about world building.
There are, generally speaking, two approaches you can take with creating a setting. You can do what most shows do and focus on the story and just make stuff up along as you go, making sure you keep everything moderately consistent -- or not. Or you can do what the writers of "Fraggle Rock" apparently did: invent an entire imaginary world from the ground up and then play in the giant sandbox.
That's kind of amazing. I can't think of another children's program that sinks so much energy in creating a consistent fantastical ecosystem. "Great Radish Famine" is the first episode that spells out explicitly the fact that we've been exploring a completely realized interconnected world.
There's a damn good reason why they spent so much time on this world, and you can think of this episode as the "Fraggle Rock" writers' thesis statement.
Up until now, we've been primarily concerned with Fraggles. We have only very briefly visited the Gorg World, and the Doozer World. Both Gorgs and Doozers have been presented to us from the Fraggles' point of view as mildly interesting (or dangerous in the Gorgs' case) Others.
This episode marks our first extensive visit to the Gorg and Doozer worlds. In particular, this is the first time Doozers become actual people to us viewers. Up until now they had about ten lines of dialogue in total and were basically fantasy Mound Termites -- if Mound Termites were adorable little bug-people who build their giant nests out of piles of candy. They'd be developed even more in later episodes, as would the Gorgs (we'll get to them tomorrow).
The key concept in this series is that all three of these species are intelligent, noble, profound, and dependent on each-other in some way or other -- and each one thinks that they have nothing in common with the other two. And the brilliant thing is that, in point of fact, Fraggles are very different from Doozers who are in turn very different from Gorgs. This episode throws them all into a crisis with apocalyptic stakes and if they're ever going to survive it, they need to at least acknowledge they each depend on the other while having to deal with their differences. (Note how parts of this episode illustrate the sheer difference in scale between the three worlds!)
The very greatest scene in this episode happens in the last few minutes. We get one of the most genuinely sweet songs of the entire show in a scene that honestly gets me every damn time. And immediately afterwards, we see a hilarious and surprisingly cynical dip into (dare I say?) political satire.
And here's the wonderful part. After all that, we get some reassurance from a voice of authority character that even though that last scene looked bad, very bad, things are going to be alright. This was the big turning point because the various worlds are now at least aware of each-other. They know they have at least one thing in common, and it set the stage for more crossovers between the three -but really, four- worlds.