Is it on the decline? i dont know to be honest. But i wouldnt think so.
When i was younger (in my 20's lol) i trained wing chun during the day for a year and a half becouse i worked at night at the time, most of the people training in wing chun (i managed to catch the odd 6:30 pm class occasionaly aswell) were not going to join Karate or judo, they were suited to what they were doing.
I had already gained about two years of a freestyle karate previously (karate/judo blend) to my wing chun experience and they were generaly different kinds of people from different walks of life, generaly speaking ofcourse.
So i would imagine that certain peoples would always be drawn to different arts. Ofcourse im not saying one is better or worse than the other becouse there were strong practitioners in both my experiences at those venues. Maybe its more of a mindset thing, not everyone wants to bother with highkicks or showy sparring or even chainpunching, whatever their preference for self-defence training is, will define what they look for.
The young will always want something flashier and the older we get the more mature type arts we start to think about.. These days (although i practice shotokan) my interest is heavily in Bagua, i dont think i would have been so interested back in my early 20's in the Bagua.
So maybe its just the young we are talking about here, like new consumers to the latest product or something.
Meh, the Kung Fu's out there have lasted through all this before. When kickboxing was becoming known/popular it survived just fine etc. MMA is not the be all and end all. Even Krav or Systema, theres nothing new there, no new invented techniques lol.
How about gouging someones eye out, is that in MMA?
I can tell you that MuayThai and BJJ are not suited to my daughter for egsample, i hope she never does but if shes ever in some type of violent situation i dought its going to be an even weight and experience bout, we should train for worst case scenario so she will be outweighed and outstrengthed wont she, what do you suggest?
Striking/grappling just went out the window, shes gotta go for the eyes/throat/groin/knees etc all the nasty stuff right? I think Kung Fu's will survive just fine in my opinion.
my two cents
cheers