>someone had a case that burned them in some previous project and now his life mission is to prevent that from happening ever again
Isn't that what makes them senior ? If you dont want that behaviour, just hire a bunch of fresh grad.
Nope, not realizing something doesn't apply and not being able to take in arguments is cargo culting not being a senior.
No, extrapolating from one bad experience to universal approach does not make anyone senior.
There are situations where it applies and situation where it doesn't. Having the experience to see what applies in this new context is what senior (usually) means.