I enjoy his rapping because it dispels the myth that "anyone can be a rapper." This dude has been trying to become a rapper for so long and he is still just so terrible. If it was easy, he would have made at least one decent song by now.
Also, I wonder if he just keeps going and he puts on this crazy persona because he gave up a pretty solid future in skateboarding and now there is no turning back. Admitting defeat to himself or anyone else would just be too much, so he keeps on hoping (pretending) this shit has a chance and it isn't terrible.