Let's agree that there are no original ideas ever right? Everything in terms of knowledge is derivative. Same applies to bjj. People flock to Danaher and his tidbits of knowledge because we respect his opinion, his take on certain subjects (even if they've been rehashed over and over). Have you ever taken a class from the Professor? A seminar perhaps? I'm pretty sure your opinion would be different if you did. His mind works unlike most people. There is a reason why World Champions like GSP have him in their corner.

About his prowess on the mats, sure there is very little footage of him rolling and he's never competed. His history of physical ailments is well documented. Dude just had his hip replaced last year. Does that make his mind any less lethal? Does that make his technique any less formidable? Does that make his approach to the game any less brilliant?

About him having a cult of personality, Jiu-Jitsu & martial arts in general is cultish and this is nothing new. People flock to learn from successful people, fact. When the Mendes brothers opened up AOJ, you don't think there was a stampede of people enrolling at their academy?

Why does someone who puts in the time, energy, and thought into creating successful systems and paths have to share all of his work with other people? To be dismissive of his influence and the work that he has put into this art just because you haven't seen him roll or because he hasn't given you something for free is pretty ridiculous. He's been a BB for 14 years under Renzo, probably in the game for 20+ years. About as legit as it gets.