Joe Rogan isn't the main man on all things martial but what he says is true, there are a lot of phony people out there teaching stuff that is not only impractical but some aren't even very skilled at what they do. Nobody is claiming Tommy Carruthers, Emil Martirossian, etc are phony just that they aren't great martial artists and it is silly to claim they are, the only people that appear to do so are not surprisingly their students or Instructors or people that have watched many martial arts movie and maybe believe Jean Claude Van Damme, Jet Li, etc are the best in the world also.
Bas Rutten has done many different arts and has fought in MMA & had many a street fight some well documented whilst he recommends arts like Krav Maga for self defence especially as he mentions it can be learned fast, not everything he does regarding self defence is from Krav Maga. Worth considering also not all Krav Maga is the same, just as all Wing Chun isn't - the approaches of Itay Gil, Amir Perets (Bas Rutten's friend) etc differ a lot from the commercial civilian stuff you see taught, Military Krav Maga you rarely see taught to civilians.
Joe Rogan isn't claiming everyone that teaches self defence is a phony, he is just saying there are many out there who are or that there background and claims are suspect to say the least e.g.
^ These are people with schools worldwide,books and DVD's out,that have been on magazine covers,on TV programmes, etc.
People like Frank Dux claimed they fought in secret tournaments, the film 'Bloodsport' with Van Damme was based on him, others claim things like winner of 300 no rules street fights, etc - none of these claims they can substantiate. Train with people with backgrounds and claims that check out,and train with high level people in different arts not to learn entire arts but to have a good idea of what works and what doesn't against a skilled opponent e.g. nobody has come out with a list of world renowned grapplers Tommy Carruthers has been on the mat with. Thinking how what you do can deal with other arts or scenarios is good but you have to go out and train with exceptional people in those arts to really know what works and what doesn't beyond the theoretical stage. Having your friend in a class trying to take you down or pretending to be a grappler, is different than facing a real experienced one.
If you train with Tommy Carruthers, Emil Martirossian, etc - then go along to a good MMA gym for a while and seek out renowned specialists in self defence with verifiable backgrounds. What have you got to lose? Thinking Tommy or Emil, etc one man has the answers to everything or is all you need for reality based self defence is very naive indeed or thinking their experience in martial arts and self defence is so much more comprehensive than others again is very naive indeed.