Unironically every reason it's fake, if you jump on duckduckgo, you'll find actual science people explain the engineering and logic behind why it worked. My favorite was a coworker of mine who tried to prove it was fake by telling me how thin the skin was, that a screwdriver fell right through the skin, etc. and I sent him information regarding the pressures inside soda cans and the thickness thereof, compared to the apollo capsule. I think that finally got through to him.