I believe someone with no training "can" stop any attacker...like the Indian girl and the 2 AK wielding home invaders. (Note "can" denotes possibility, "will" depends on a host of factors, training is only one) How would it go a 120lb woman vs a big, trained, Somoan..., in a fight? Predictably for her, she'd (and I'd probably) get trashed. The point of what TFT teaches...is what would happen in a "fight" (where 2 people are knowingly engaging each other, they each know "what's up") doesn't matter in violence. Real violence is sudden and is one person injuring another. Not hurting or fighting, but injuring to shut them down. Think serial killer. To survive, you need to be causing the injuries. Any human can injure any other, actually doing it takes more will than skill.
Can a 120lb woman dig the eye out of the skull (rupture the orb) of a 270lb Samoan? Yup, will she? Don't know...will she get the opportunity? Maybe not, but there are other areas if the eye isn't available.
I'm sure we'll agree to disagree on the marketing (and the rest of it!)...but I'd be interested as to what training you'd recommend for someone to stake their life on? Is it publicly available, do they have a website? (I'd love to see their marketing, bet I could pick it apart just as easily, or they aren't selling much).
Do you believe a 120lbs woman can do anything to protect herself realistically against a bigger, stronger assailant? (...and they will all be bigger and stronger than her). Should she train at all? If so, what? Or...not bother since she is doomed to a life of victim-hood due to her small stature.
Should I bother to even engage someone who out-masses me by say 40lbs of muscle if I'm attacked? If I did prevail, would it be due to my size or strength (nope, I'm smaller & weaker in this example). Due to skill & reflexes? Due to using all of the mass I do have against whatever vulnerable anatomy is available until they (or I) are too injured to continue? I'm thinking a rock to the back of the head (repeatedly) would work, or knocking them down and stomping their skull until they don't twitch. How do I knock them down? Well, I guess that's up to me to figure out. Criminals sure figure it out just fine.
The bottom line is small, untrained people actually prevail against larger, stronger attackers all the time, it is newsworthy. The rub is...are those results repeatable? What did they do right? What are the odds, are there methods that can change those odds from "got lucky" to "very good chance?"
Now we're getting somewhere with some meat to discuss. As I look again at the picture, it is clear it was staged which makes sense. Hard to get a photo in motion to come out that clear.
This means (as with any photo) you do not have any context, so you applied your own. Understandable, but his method of striking is completely different than a MT knee. He is not merely lifting his leg and he didn't start that close. Ironically, they would completely agree with your statements about not striking by merely pushing out an arm or leg...TFT teaches to strike using all of your body weight and complete penetration so that when the strike is finished, you are standing on the spot he was occupying.
So: his foot is flat for balance and to keep force from leaking into him on contact dropping his plant heel back down (equal & opposite reaction). He doesn't need (and can't) drive his hips separately as he is driving his entire body through the opponent, all 240lbs of him. He isn't extending the knee, then retracting it. After the strike is done, he'll be standing over the guy (since the other guy started kneeling).
I know you aren't ever gonna think this is anything but crap...but that isn't why I'm responding (I just like to discuss training). Without seeing a video of how he is striking, the photo is meaningless. Picturing him running, then kneeing the guy in the sternum as he runs him over...would be a better mental picture than picturing him standing where his feet are in the photo and lifting his leg up.
I enjoy the discussion at any rate. I do believe that any human adult is capable of taking out any other human...the day I stop believing that may be the day some 120lb teenage punk takes me out because I did something stupid due to overconfidence.
One of the most brutal attacks I've seen (stark in it's instant effectiveness) was when a person walked by and someone standing to the side hit them in the base of the skull from behind with a bat. Instant death and no human in the world can withstand that..not your 270# Samoan, not if the bat was swung by a 120lb girl (provided she knew how to swing it). So...I see my training task as how to get as close as possible to that perfect efficiency with just my body...unless I have a bat!(or my gun
)
Do you teach Muay Thai for free? If so, good for you. I'm a greedy capitalist thinking of all the ways I'm gonna spend that ten dollar bill myself. 
