This is an absolute masterpiece. Hats off and congadulations.
The main thing about BS is how well it is written. Yeah, there's the music and the art and the spirituality, yadda yadda, et cetera et cetera, but it is mainly just a well told story. The idea for the story alone is gold, and you presented it masterfully. The language of BS is what makes it a unique and downright good work.
This is why so many found it boring, I think. Not because they are dumb, or unwilling to see the artistic viewpoint, but because it feels, to me at least, more like a novel than an animation. Of course, it might just be me, so I guess this paragraph is somewhat pointless.
Now, I'm not trying to put all the other elements- the art, music and themes- down. Quite the contrary, they were all excellent. But to me they seemed to be more supportive of the writing, adding to and accentuating what is already a masterful command of the english language. Bravo.