Second of all, no Japan's major economical gains are not rooted in the anime industry. Anime in Japan is not a country-wide phenomenon that everyone loves and reads. Anime is read/watched and made in Japan by pretty much the same people that read/watch and make comics here in America. So, no, gutting the industry wouldn't completely destroy Japan and make it explode off the map.
More to the point of the article, censorship is a slippery slope. But, it's definitely one that's necessary to attempt because the alternative is no censorship. This is difficult for a lot of the posters to understand here, mostly because, unless by pure accident, many of them don't have children. If they did, or if they had basic interaction with children outside of the anime world, they'd realize first and foremost that children will get their hands on everything. What's that, mom? Don't buy the comic book called "Yada-yada"? You got it; in no way shape or form will forbiddence turn that into a forever tempting mystery. And if you respond with "Well clearly those are terrible parents who never watch their children" then congratulations, because you sprouted from the ground at the age of 16 or you were shackled to a wall until you were 16. However, you do drastically cut down on the number of children exposed if you take the care to separate what's meant for more adult minds and what's more child-friendly. This is really a non-issue with books, movies, and artwork as long as the packaging isn't overly explicit. Adult books aren't exactly appealing to youngsters as the subject matter usually isn't interesting enough for them to sit through it long enough. Movies can't be bought outright (ZOMG! censorship means I have to be 17 to buy this, or at least look old enough), and a kid can't exactly sit in the aisle of the store and thumb through a movie. Art is interpretive as it is presented in still-form and without context, subject to the observer's mindset. But comic books provide the graphic representation of movies with the easy accessibility of books. So, for the same reason that Playboy and Hustler and packaged in those black plastic bags with the YOU MUST BE 18 TO BUY stamp on them, it's not exactly unreasonable to ask that anime with sexual themes or tones of incest or underage be put towards the back with the adult materials. Christ, Oedipus married and banged his mom by accident, and even he had the decency to put out his own eyes afterwards.