I watched it on occasion when I was younger and enjoyed it. I too saw an episode over the weekend on Boomerang.
And boy, was it terrible. I'm all for teaching kids (or anyone) about the environment, but the whole thing is a public service announcement disguised as entertainment. And in addition to being a propaganda tool, the show itself sucks. The characters are written to be so politically correct that they become stereotypical and annoying. Or maybe they're just annoying becuase the dialogue is awful. The plots were awful too, even for the subject matter. It's sad that Captain Planet himself was the best character in the show, because he's really lame. I don't think the creators of the show even tried to make an interesting superhero. Actually, I don't think they cared about quality at all. They knew only kids would watch it, and that they didn't know what quality was. Bastards.