Yeah there is a lot of video that produces evidence that the training isn't very good. There is a lot less video that supports it as good training.
There are a lot of aspects in the training that contradict training with more video,anecdotal, expert, training and competition evidence.
You cant really see any resisted training. There is no real training against other styles there is no competition and experts who have done more than one method of training suggest it doesn't compare favorably.
There are some personal accounts that support the training and that is about it.
Which for me would be not enough data.
Plenty of things have the evidence of personal accounts. But do you really want to be the magnetic wristband of martial arts.