Depends because sharing logic like that can be dangerous. Each system is going to have exceptions and unique properties, and SOME will leak into the shared space. This is a hard problem. If what you were saying were true, software would be perfect. It's not though, it sucks ass.

I mean, try writing an API for 100 different consumers with different needs. Good luck! They're gonna ask you for X ... Z and B depends on F but F can't exist with C and C is just a bad idea overall but also O is there and that changes things and...