I only know about Karl because /k/logs won't shut up about him whenever Ian is brought up. He's a cuck which is plenty of reason to avoid watching him in an already saturated market. But I feel like I should play satanist's advocate:
He helped design a rifle with widespread acclaim, going to tattle to Brownells on twitter is gay.
He is IRL friends with Ian, C&Rsenal, James Reaves, and even Dugan Ashley, so he can't be all bad. In one of their podcasts Othais said, (paraphrasing heavily), "Karl is an edgelord that loves to argue for the sake of arguing. " That sheds some light on why he would share very inflammatory views when it would obviously piss off his audience, everyone acts more retarded on the internet than they do IRL. It doesn't do much to explain why he would admit he was a cuck, or proudly announcing he's a satanist when he has a business deal with a very conservative company, that's just oversharing indicative of a budding lolcow.
If anyone that still likes him is reading this, they should probably tell him to cool it with purposefully trying to piss off and pick fights with his core audience and business partners, that has never ended in anything but a top-tier lolcow.