IMO, in general, some music resonates more with the "masses" than other music. The more that music resonates with people in any way (generally, emotionally), the more it is accepted as "popular" music. The less the music resonates with wide audiences, the less popular it is, and it lives in the vast "underground" of the music world. This stuff is deep inside the underground and probably only has fans amongst those with extreme tastes, vast tolerance, or intellectual appreciation for such things. Probably 1/10th of 1% of the general public, if exposed to this, would listen for more than 20 seconds before shutting it out.
The 2 pieces performed might come across better if they were an accompaniment to a movie or visual arts/dance performance of some kind. On their own, they are really HARD listening IMO.
I don't think I'd want either of these geeky Elliot guys rehearsing these pieces for hours on end anywhere NEAR me...but they do make some cool "guitar-gasm" faces.