There is no accounting for taste.
It boggles my mind that movies like Transformers 2, Garfield, National Treasure 2, and Alvin and the Chipmunks 2 do so well commercially (for clarification's sake, I think it's important to note that "failure" means commercial failure in most uses of the term in the movie industry). Perhaps it's a sign of our society, or perhaps I just have bad taste. I cringe when I hear lines like those cited from ____ or Avatar. The lines don't ruin the movie for me, but I do think "c'mon, really?!"
As for PatF, I think as it stands, it's a commercial failure. I don't recall it being explicitly touted as being as good as the hand drawn classics, but they certainly compared it to the early 1990s films, and the implicit suggestion was that it would restore Disney hand drawn animation to its glory. Regardless of how much the film itself cost, the money spent on advertising makes it undeniable that Disney had huge expectations for the film, and wasn't putting it out there as a film at a lower tier than the 90s classics. In light of the box office numbers thus far, I don't think that's happened. Conversely, it has not been a failure, either.
However, given the quality of the film, a lot can change between now and say, 5 or even 40 years from now. DVD, Blu-ray, merchandise, etc., sales all make a big difference, as do the inherent values in the intellectual property from the film itself (are the characters memorable? can they market them in the future, use them in the parks? etc.). I guess what I'm saying is that although the film hasn't been as profitable as expected thus far, it's far too early to count it out. A lot depends on how Disney plays its cards with the film for its home release and beyond. Then, we'll know how it fits into the canon of Disney animated releases.