If by SAS you mean SSH, then really it's that there's a much smaller client surface area (really, openssh), and the fallback is always "use a PKCS#8 private key", which is much more uniform than SSL. SSL mixes in x509, and protocol, and UX.
That said, you don't have to agree with it. My macro point was really assessing these things against basic security threat modeling, not whether or not you agree with our choices of using SSH.