If you need to completely revoke someone's account overnight to prevent adverse impact, you designed your "access matrix" incorrectly.
This doesn't make any sense to me, and is in fact exactly how it should work.
So you're telling me that every time, say, a CS rep needs to access some sensitive customer information (which is almost every single call), you think they should need to go through some password approval process? Security procedures that are so cumbersome to getting work done get bypassed.
The whole point of SSO systems is that you can immediately revoke access to any and all systems at once by just changing one setting.
But indeed, permanent access to sensitive info without ever needing approval from a second person (beyond being hired and gaining the access) seems like a bad idea.