And while maybe a Wordpress bug could "only" lead to a user password database leaked but not the complete system compromised, there is a valid question which is actually worse from case to case.
Point is just that from a different angle, things are maybe not so clear.
Software written in memory unsafe languages is among the most used on the planet, and could in many cases not realistically replaced by safer languages today. It could also be the case that while bug-per-line might be higher with unsafe languages, the bang-for-buck (useful functionality per line) is often higher as well (I seriously think it could be true).
By comparison memory safety bugs and shell script bugs mostly occur in specific classes of languages. It is therefore natural to ask for new languages in these classes to pay more attention to eliminate those sort of bugs. And it is, while not satisfactory, okay to answer in negative while acknowledging those concerns---Hare is not my language after all. Drew didn't, and I took a great care to say just "not a good response" instead of something stronger for the reason.
I really have to disagree on this, in spite of not being a security professional, because the history has proven that even a single byte of unexpected write---either via buffer overflow or dangling pointer---can be disastrous. Honestly I'm not very interested in other aspects of memory safety, it would be even okay that such unexpected write reliably crashes the process or equivalent. But that single aspect of memory safety is very much crucial and disavowing it is not a good response.
> [...] the #1 way to improve security is to reduce complexity, [...]
I should also note that many seemingly simple approaches are complex in other ways. Reducing apparent complexity may or may not reduce latent complexity.