I honestly give him a lot of credit for that kind of movie, but there's a reason why kid's movies are the way they are. Older kids find anything made for kids, well, childish, and therefore they go to movies for slightly older audiences. Most kid's movies (the bad ones) tend to play the younger audience because those are the ones that drag the family to see movies and scream forever in the store for the merchandise. A long, involved storyline will bore the heck out of little kids unless it's animated and has wacky sidekicks, older kids who weren't turned off by it being for kids would definitely be turned off by the esoteric subject matter. Unless they're like 9-14 year old film school wannabees or knowitalls, there was nothing appealing about the film on any level of general public film going. Even the marketing department was like "huh?" and that's why they made it look like a Harry Potter Clone (right down to the similar font). And I guess making it look like just another awful HP ripoff (after the films ended, too) scared even more potential moviegoers off.It's as if Scorsese was trying to make a kids' movie, but utilizing the stuff he would have liked as a kid -- in this case, the early era of cinema. Something that few of Hugo's intended audience would appreciate as much as him, but adults who would be would probably find it too whimsical. This Cracked Photoplasty says it all.
http://static.tvtropes.org/pmwiki/pub/images/rsz_hugo_8866.jpg
But I bring up Hugo because that seems to be the kid's movie film snobs love to bring up because all the other kid's movies are incredibly awful because they're not as artistic (read: offputtingly stuck up). Hugo is an example of how not to make a kid's movie on the upperscale end. In contrast you look at the "all kids are morons" end of the scale and you get Marmaduke. A movie that was painfully generic as far as kid's movies go, based on (with all due respect to the creator who just passed away) a comic strip that wasn't strong enough to support a story to begin with that no one under the age of 40 knew about other than reference.
And this brings my point all the way back home... Pixar and Disney's in house CGI studio manage to strike that great middle point of high quality animated movies that both kids and adults can enjoy. And with Pixar, they play the field all the way around. Up made kids care about a movie starring an old guy. They managed to have the heart of an indie movie (a movie of which would just have been the beginning 10 minutes stretched out for 120 minutes with the melodramatic angle ratched up), with all the fun of an exciting adventure. And whatever anyone has to say about Cars, they followed up some devastatingly emotional movies with one that, while still heartfelt, was just a fun movie for the younger audiences that admittedly was pretty good. Even the second one, clearly made out of desire to sell more die cast cars, was a lot less cynical than most. I mean, SharkTale was pretty freaking cynical a cash-grab there could be.