First comment at the article makes a rather solid point: when it ran an initial story this morning about the app being approved, Gizmodo characterized Forchan as a "porn app":
To be fair, that first story ends by saying forChan is "truly innocuous until you enter a web address in the URL field", that removing it would "set yet another dangerous precedent", and that Safari "does exactly what forChan does".
Primarily because the first sensationalist article may very well be both the way Apple found out about this app and the very reason they had to clamp down on it - if <conservative parent> sees that gizmodo headline taken up elsewhere, they could be very reasonably expected to think "oh no! Little Timmy has an iphone! He can now look at pornography!"
The second article is another sensationalist piece, but this is made much worse by the fact it is feeding off the very activity it probably caused with the first.
If your newspaper of choice ran a story decrying a particular building as the source of all the worst crime in the city one day, and after a police crackdown ran a piece talking about police abusing their powers or judges granting search warrants willy-nilly, would you be okay with it?
I'm not sure the app is (was) a pure image browser. The dev said: "There is currently over 100,000 pics spread between 15 categories with much much more coming soon." The "categories" thing makes no sense unless the app was able to associate specific sites/boards with certain categories ("blondes, brunettes...") somehow, either by linking to the boards directly or by detecting a "known" categorized board/subboard when the user browsed to it.
Bottom line is that if there were any nudity/porn sites included in the URLs that enabled the "category" feature, the takedown was probably justified.
http://gizmodo.com/5445065/apple-approves-porn-app-in-under-...
But now that it's been pulled from the store, Gizmodo changes to representing it as "exactly the same as Safari" and downplays the porn aspect.
(and note that the two Gizmodo stories were posted 90 minutes apart -- amazing how quickly Gizmodo moved to completely reframe the story...)