well then I guess the marketing department wasn't as powerful in the other countries or they didn't have the super-duper research that said philosopher was a 'bad' word to have in a book title (like the supposed statistic that books with variations on Dead sell an average of 25% less than a book without the word in the title), and so it never occured to them there was any 'reasonable' reason to change it.
But it had nothing to do with the intelligence level of American children. Noone said, "american boys are stupid and can't read so we can't have a big words in a title." Rather they made the intellectual leap that sorcerer would be more appealing (oh it's about magic and fun things, I'll read that!) than philosopher (wassat? old dusty books? I like action, buggeroff, hey a wrestling book!«child wanders away»)
I do not like that it was changed, but I understand why it was changed, much more sensible are a handful of brittishisms that were changed, although I'd prefer the original there as well, I for one was never able to make the prodigious mental leap that torch=flashlight until it was explained to me.

Back on topic, the pixar title is just unpronounceable, damn french vowels, noone in america will ever get those right, if it were german, spanish, or even latin they'd have a better chance. Hell you get pretty decent luck with Japanese words most of the time, but on this one I can't even get a consistent spelling in my brain, much less a consistent pronunciation.
as a handful of examples (believe me there are many more) I've thought it was (having seen this thread title many times) :
Rat-ill
Rat-too-lay
Rat-ah-Lee
Rat-ah-too-eh-lee-Ay
Rat-ah-twee
Rat-ah-too-EL-ee
Rat-ah-too-ee
Rat-ill-ee
Rat-too-ee
Rah-tat (+above variations whereever Rat was used)
I just loath that ouille combination, for some reason i can't visually parse the word in my mind because of it. heh, separate that thing out and it makes me think the damn film is titled Rat-oil, with the oil drawn out aristocratically , dahling.