You could write War and Peace-length books that discuss the various issues this show brings up. The sexual side is definitely there, and I think this writer brought in some great insights, including a discussion of the show's fixation on nudity, which I've brought up here several times. The question becomes whether the writer, "Squiddi," is reading too much into the episodes, especially "Karate Choppers." But others would say, "that's the point"--you can never read too much into a given work, be it a movie, a cartoon, a painting, a video game, a TV show, etc., etc., etc. It's precisely the multiple meanings that different people can get out of a given work that, in part, gives it that staying power. Squiddi's statement near the end regarding children and adults, that "Both can sit in the living room together and laugh for different reasons" is partially what makes the show so popular and successful. As I've said in previous posts, children aren't going to get 99% of these sexual innuendos. They'll watch "Karate Choppers" and never come near the conclusions Squiddi did. At least, we hope they won't. (If they do, there's entirely different issues to be concerned with....)
Again, you could discuss these issues seemingly forever. For instance, I've discussed in previous posts about such episodes as "The Secret Box," which has some very deep underlying themes about the complexity of interpersonal relationships, and "Club Spongebob," which has religious themes galore, even if religion itself is never mentioned beyond Patrick's statement "Maybe he's [Squidward's] not a brother."
Through (primarily) the character of Mr. Krabs, this show speaks volumes about the effects of capitalism upon our world and our psyches. The writers foreground the irrationality of capitalism, for example, in the episode "Culture Shock" when Mr. Krabs falls on (and breaks!) one of his tables, just to beat Spongebob to the penny. This begs the question, "isn't the table worth more than the penny?" We see both the greed and the disruption of human relationships in the episode "One Krabs Trash." Think about it: once Mr. Krabs discovers how much the soda-drinking hat is worth, why not simply tell Spongebob himself? Instead, intent on getting the full value for only himself, Mr. Krabs goes to absurd lengths to get the hat away from Spongebob.
There are more examples, to be sure. However, the 2 episodes that best exemplify the effects of capitalism are "Squid on Strike" and "Born Again Krabs." There are underlying messages galore that are every bit as deep as what Squiddi wrote about regarding sexual themes.
Anyway, the article was interesting, and I think Squiddi definitely made some great points in as objective a manner as possible.