Interesting thread this. I could not get the link to work so I have not viewed the guy on You Tube. But it seems that the original question of "Does anyone know who he is?" immediately got ignored and an indepth discussion ensued about whether the guy is a bassist or not as apparrently, he uses higher register tuning.
Without having seen this, my opinion is, music is music no matter what you play it on. If you're also good at it as well, that makes you a musician. I trust some/most of you will have heard of Brian Bromberg. Love him or hate him, he is a well respected world class upright and electric bass player and composer. His album "You know that feeling" has no "guitars" on it whatsoever. All guitar parts are played on the bass or variations of such. ie, piccolos etc using effects. I don't know many guitarists who could play those parts on guitars as well as he can let alone on a bass. It's purely an extension of the musical instrument preconceived idea that we have in our heads as to who should play what, on what and what it should sound like.
It's all relevent in the world of music as far as I'm concerned and is no different from a bass player using a distortion pedal because that's not what a bass sounds like really is it? I wonder if all the upright bass players of the 50's slagged off the first guy they saw with a Precision and said it's not really a bass but an electrified plank of wood. Probably not.
If the guy is good, plays his stuff on a bass of some kind, then he's probably a good bass player.