Earlier quoted context omitted.
> This attitude is cancer. Let me throw another quote at you Nonsense, defence in depth is a core security principle. You should not rely on a single control to protect you.
Really, the issue here is that security is never treated quantitatively. At least in my experience - are there examples of quantitative security? In some sense, the problem is that the goal is zero controls breaking, but of course, that also provides no information on security. Intuitively, it would seem that parameterizing security (in a diagnostically useful way) would also require a number of quite different measu…
But the way risk is managed in the industry (multiplying likelihood and impact) is completely incoherent and voodoo. See the book "How to Measure Anything in Cybersecurity Risk" [1] for a good explanation of why it doesn't work and better ways to do it.
Which is a long way of saying, no, security doesn't use quantitative techniques mostly, but it would be possible if people understood how to measure and manage risk properly.
[1] https://onlinelibrary.wiley.com/doi/book/10.1002/97811198923...