I've already commented on the matter before and in depth, but let me say that I pretty much agree 100% with Butcher. This continual complaint that no one's making comics for kids anymore is nonsense -- there hasn't been this many comics for kids since the Golden Age era and the quality is in general considerably higher overall (Secret Science Alliance y'all!). I think part of the problem, apart from the reasons Butcher lists above, is that the Western comics audience has become more and more fragmented and insular in their particular interests. By and large, the superhero fans don't mix with the manga kids who don't mix with the indie crowd who don't show any interest in the kiddie books.
Also: Heidi MacDonald offers similar thoughts on the matter here.