Brother Bear was classic storytelling and a good story at that. Most of the failure of brother bear came from the techniques used in animation. Many people were disappointed and unimpressed that Disney went back to 2D "old style" animation for this film. There were no modern techniques used such as Deep Canvass that was developed for Tarzan. I suppose that the animation was to bland for people considering the technological advances made for animation over the last decade. In other words, I believe that the general attitude was that this was a cheap film designed to create a quick profit for Disney. I personally believe that Disney created this film with basic animation on purpose because it is truely representative of what was done up until the late 80's. I don't think they went cheaper, I think that they tried traditional and the plan was not as well recieved as they would have liked. It is clear that Brother Bear was a very well planned out story so I question the idea that it was just thrown out there in the hopes that it would turn a profit.
There have been rumors that a Brother Bear attraction would be best suited for a river ride in Canada (epcot). Perhaps this was on the drawing boards. I know that there has been a thread about this in the past if you care to search for it. As of right now though, I doubt that a new attraction would be themed after Brother Bear because it wasn't widely popular.