How many really truly secure C programs have ever been released into the wild? Maybe qmail? But qmail did it by completely rewriting the C standard library.
I'd say OpenSSH (since SSH2) has a better track record than most webapps, as unfair a comparison as that is. In terms of local robustness, there's SeL4, which is also a bit unfair (since it took about a decade for a team of geniuses to prove enough properties to make it probably not very buggy).
I don't disagree with your use of OpenSSH as an example.