Majority of present and past staff have come though either APD and R&R simply because it give you a platform for visibility. Walt and Mason are currently the only 2 staff who aren't former seniors of a faction, even Millennium though he was an APD rat started batting for team civ.
I'd counter that making mod without going though a faction only makes representing the playerbase more advantageous.
As for SAPD sitting in channels not interacting with the lower lifeforms I completely understand why. The johnson smooching can get quite intense. It's why I don't talk to the mods.