You'd need to ask someone who thinks it's a good idea to keep a massive oversupply for the military. (Note that I'm not American, so I have no skin in that game.)
I don't, though, disagree with keeping a large stockpile of goods.* I just disagree with constantly kneejerk reassigning production to it.
* I still don't know that it can work, but only because I think people too quickly forget that it's important. If people could be convinced otherwise in the long term, I think it's a great idea.
Most people would accept that epidemics (let alone pandemics) are bad enough on their own. Many people would say bad enough to avoid a Just In Time approach to public health.
If that's OK, why not do that for health related issues too?