Thing is, you are free to buy that or buy another cheaper watch with that movement in it. Depends if you want a 'Cartier' or not.
I mean I get it, I could buy plenty of cheaper watches with Selitta SW200s in them, but I don't cos I like TAG. I can moan about it all I like, but I still buy them. And no doubt when they release an in house Aquaracer I will moan about that cos it's too expensive.
But yeah, I agree you can make a case that they are charging £9000 for a £1200 watch. But there isn't a single big Swiss watch company that offers actual value for money for materials used.