More evidence than allowing root to log in with any long password?
I have to admit that I am a bit disappointed in this kind of thinking. There's vulnerabilities everywhere as especially the past few weeks have shown.
One occurrence is not a statistic and should not be used as evidence - it's just an example of a vulnerability that due to various bad circumstances lead to a particularity bad outcome. This logic is in my opinion equally flawed as calling alpine safe now because this particular vulnerability has been fixed.
I'm not a big fan of blaming and I think it's just a result of bad circumstances, but it's interesting to see how some seem to blame musl, but one could argue further that musl documented the behavior of their API which was ignored by openssh and so on
This particular flaw sat latent for a decade.
There's a good chance similar flaws will be discovered elsewhere.