In my opinion, throughout my research on CMA, all of the stance work and forms were just their way of strength training. China was and is a very poor place so they used what they had. Forms can be very strenuous when done correctly, as you're working out your legs in a deep stance, your abdomen and lower back when you tense it as you go through the moves and shoulders back and arm muscles when doing hand techniques. I've also seen people doing the horse stance while supporting another person on their shoulders. Back then, they couldn't just go to Gold's Gym and get on the machines. Unfortunately, these exercises were the only ones taken from CMA and now people think that it's all they need to kick ass. I've also seen people lifting logs or cement bricks, and a lot of bodyweight exercises as well. Now that we have modern equipment, you don't have to go out and cut down a tree to do some bench presses, but I believe forms and stance work still have their place. The forms were a clever way of putting it all (balance, strength & technique) into one set of exercises. That's all they are. The problem is they've dominated importance in CMA gyms all over now because it looks the most interesting, which is why kung fu is so popular here anyways.
If you've ever looked inside one of (the boxer) Ross Enamait's books, you'll see he has a whole section on "warrior animal training". In there he's doing a bunch of crazy looking things but they really work out your core and i've seen them done in CMA practice as well.
The problem here is a majority of ignorant fucks who want to look pretty doing kung fu when fighting is never about being pretty. Please, don't make any comments on how your sister loves Vitor Belfort.