When SpaceX launches a rocket, they think it will work.
When NASA launches a rocket they know it will work.
The cost of going from "I think this will work" to "I know this will work" is really expensive. It might be cheaper/faster to fail a few times and fix those problems than it would be to verify everything up front.
The cost of going from "I think this will work" to "I know this will work" is really expensive. It might be cheaper/faster to fail a few times and fix those problems than it would be to verify everything up front.