No, not an argument, good questions...Not trying to argue but I'm more talking about day to day operations. Reprogramming and/or rekeying radios would be very much doable for larger long lasting incidents, I'm more talking about being able to have situational awareness.
I don't work with SVRIA, so I'm not sure exactly how they are set up.Do the system managers in the region coordinate keys between systems? So as an example SVRIA would use key "1" in slot 1 and EBRICS would use key "2" in slot 2, or something along that line? Again thinking about a CHP scenario when perhaps both systems are programmed into the radios. That also would obviously require the radio to except multiple keys.
But usually on large systems like this there is some very good design practices that go into place to handle this sort of stuff. It's not one guy sitting in an office somewhere randomly making decisions and not sharing info.
Sharing keys between agencies is certainly done. It's very carefully handled though, and the guys that do it know that they cannot be shared/leaked.
Radios can accept multiple keys, so that's not an issue.
And there are other ways around this. The agencies have retained their old systems (UHF in the case of SJPD) and dispatchers can patch to those if needed. Dispatchers can also pass traffic as needed to other users.
In the initial stages of an incident, it may require the dispatcher involved, but often there will be some coordination between those involved to change to a specific interop channel if things get to that point.
I think where you might be going with this is that agencies/groups refusing to share info. That does happen on some systems, but most well run ones don't fall into that.
In other words, encryption with proper management isn't a bad thing. It actually works well. I know it's a pain for scanner listeners, but I can assure you that at no point in any system design meetings I've been involved in does the concerns of the hobbyists even come up.