Safety isn't as much determined by your aspirations, as it is by your record. 37% failure is an acceptable milestone considering all the SpaceX has achieved in its short lifetime, but I doubt would satisfy NASA's safety regulations for human spaceflight.
Not counting their initial failures, SpaceX has had a 100% success rate. And each rocket was so significantly different from the previous rocket[1], that it's more fair to say they had 3 rocket models with 100% failure, rather than one model with 60% failure rate. And the Falcon 9 has a 100% success rate. And they were awarded this contract, so obviously NASA believes they can achieve the desired reliability and safety for the rocket that will be used under the contract (not F1).
I'm not affiliated with SpaceX, nor trying to be a fanboi, but I believe you are distorting things.
[1] Which did earn them a lot of criticism from the industry, actually
That's not what I'm saying at all. Every shuttle was designed the same. Every F1 that failed had a different design, and the company's policies and practices changed drastically over that time as well. You can't compare it to an established program with intermittent failures.
Suspect you may be confusing the state of 'being safe', with the measurement of 'being safe'. Empirical methods are not the only way to quantify something.
Either world view relies on
"Just trust me, I know"
or
"The numbers never lie"
