I went to one Karate school, one Wing Chun school, 2 JJJ schools and all Sensi did not have a positive view of MMA - they classed it as a sport rather than true Martial Arts which is fine but slightly narrow minded. At the very end of the day you have enjoy what you are doing and if you are doing it for self defense then hopefully it's relevant to different situations.
At Karate & Wing Chun I asked what should I do if the fight ends up on the floor? Both times I didn't get a satisfactory response.
At JJJ they covered absolutely everything, standup, ground, weapons etc. I just fond the pace slow and the belt system slightly restrictive. I grappled with someone a belt above beginner and after I submitted him twice he complained that I wasn't wearing a GI so he couldn't grip me properly...
I took a semester of Japanese JJ in Portland, Oregon and absolutely hated it. It was incredibly (overly) structured in stance (most of it wrong for street-defense, like punching from the hip). It reminded me alot of Tae Kwon Do. Nothing at all like BJJ.
Maybe it was just a bad school and maybe it didn't even accurately represent Japanese JJ. For me, a good school emphasizes faster, fluid (realistic) movements and less emphasis on minute details like "your foot needs to be half an inch forward" or "your wrist needs to be turned 15 degrees more counter-clockwise". Unless you just don't care about the self-defense aspect of martial arts, this kind of garbage is better left for a Japanese tea ceremony (which I think is garbage, too).