Hey all this my first post here I had to comment on the post the OP made even though he himself has not been back to defend his statement.
Firstly I have trained in some form of Martial Art since I was 7 years old. I first started in Shotokan Karate and trained for probably 4-5 years obtaining a purple belt with 1 stripe. In high school I joined a Boxing gym and I trained there for another 4 years until I graduated. After a few years away from any type of training I returned to start training in JKD since I always found "Bruce Lee" style interesting but I was forced to cut that short after 2 months because of an injury. After I healed MMA was on the rise so I started training at a few places experiencing BJJ, Muay Thai and other fighting concepts. I did that for 3 years and reinjured my back and was forced to stop. So for the past 4 years I have done nothing and I have recently returned to Martial arts this time training in Wing Chun.
Now that my background is out of the way I can say that MMA is a phenominal sport. Training in any MMA gym will push you to your body's limits and beyond. I have great respect for what these athletes do and their fighting skills are top notch. With that said I digress that it is a "sport" MMA practitioners are not learning how to defend themselves in life or death situations they are training for a cage fight with a certain set of rules that are to be followed. Practitoners of say "Krav Maga, Kajukenbo, Wing Chun" are learning self defense and the preservation of their life in a potential "Mortal Combat" situation. So in theory it's not even comparing Apples-to-Apples.
People who say "Oh an MMA fighter would destroy a Wing Chun Fighter" well what are the circumstances? Are they in cage with rules 5 mintue rounds and scoring? I'd say 98% chance yes. In a life or death fight hmmm not so much. Again I am not trying to say one is better than another. I am just trying to point out a huge difference in both. You could argue that a huge part of MMA is Brazilian Ju-Jitsu which does have many real world applications but even what is taught in MMA gyms of BJJ are with the intent to use in the sport not in a street fight. Think about it, if you take me down or vice versa are we going to sit in guard hand fight or try to pass guard and then you try to armbar or triangle choke me? Am I not going to use anything in my power to stop you? I've been in street fights before, i've used anything to my advantage. I've bitten people, attacked the groin, eyes, ears etc whatever i had to do to win. Again pointing out how it's very different training at work here.
In my first day of Wing Chun training along with learning "stance" which is the foundation from which ANY martial art starts, I was taught 2 "techniques" that could potentially kill an attacker. That is not to say that it should be used to do that, but if I had to I could. Also a simple turn of a hand in a certain direction goes from a seriously painful attack to a death blow (no not "Dim-Mak" I'm talking more about attacks at the face or neck area). Another great little story, that same first day my Sifu asked me to punch him. I asked him "like this? (slowly throwing a weak telagraphed punch). He replied "No attack me for real. Any punch any way. Face body whatever and how ever hard you want." I stupidly said Sifu I don't want to accidently hit you and knock you out. He replied "Trust me, you won't" So I stood there for a few seconds and unloaded a pretty decent right cross at his face (or so I thought). I didn't even see what he did. I was told he took a half step and threw a punch at the back of my hand. My hand hurt SO BAD, I mean seriously I never had my hand hurt so much in my life. Sifu told me he only hit me with about 15% power but went on to explain about a pressure point in the back of the hand that when in a closed fist and hit pretty much forces you to open your hand and the pain is pretty immense. The point being that he could hit this spot on my hand on a punch coming in not knowing where or how i was throwing this punch and the immense pain it caused (The back of my hand was sore for a week). It was a great lesson learned and also made me think more on making someone pay for attacking you. Personally for me I like knowing that if push comes to shove I have the confidence that I can attack quickly and swiftly and end a fight before it even becomes a fight (well that is my goal). Again I feel no martial art should be used to hurt someone on purpose but I firmly believe if you are going to initiate bodly harm upon me I am going to seriously make you pay for that mistake.
So this post became very long but I have respect for every Martial Art on the planet and I feel that no "system" or art" is perfect in any way shape or form. I love talking with people and learning from them what they learned. The whole comparison the OP made I feel is impossible and unmeasureable, the fact he even said Stance is un-important is laughable because one cannot run before they can walk but you cannot do EITHER without first learning how to stand! Thank you for reading my long post and I am happy to have joined this community forum and look forward to posting hopefully short posts in the future