The two development models are as different as night and day.
SpaceX indexed on rapid iteration and tolerating catastrophic failure to learn from it.
Remember, NASA didn't exactly have a flawless execution record either - they blew up a LOT of early rockets that just didn't have people on them. They also launched Saturn III rockets unmanned to test systems before putting people on the scaled up Saturn V - in fact, the Apollo 7 mission was not launched on a Saturn V because it was only going to orbit. And they still killed a few people on the pad (Apollo 1 incident).
By the way, in case you think I'm some Musk fanboy, I hope he gets antibiotic-resistant chlamydia so he can have burning urination for the rest of his days.