To add onto @Bored's issue and where I think the sense that these folks (Seraphim and Blu) have their char's at the center of things... and is something I've called out other people on-
A lot of Staffers will run a scene 'from' their character. Unfortunately, in a lot of cases, said character is either high ranking or the other people in the scene sort of cower to the side and 'err on the side of caution' into letting said Staffer PC call all the shots.
I think this is where the sense that 'maybe they shouldn't play' comes in. However, I think it's more simple than that:
Don't run important scenes from your PC.
Run one-off combat scenes, sure. 'Training' scenarios. But if plot, especially metaplot is involved, leave your own character out and run from the ST bit. Because otherwise, it does come across as having your char in the midst of things. Part of that is because, as @bored referenced... Staff PCs tend to be in important/high-ranking spots (for the reasons provided) or you get players not wanting to risk upsetting the ST, so they just fall in line.
The latter is easily resolved by just not sending your own PC on an important scene. Have a varied staff. Let other Staffers run things. Attend their events if you must. But I think something a lot of us need to learn/realize is that when running the game and manipulating the plot... we may be giving up the chance to be a part of said metaplot. And, tbh, I see no problem with that. Play other places to get the 'just a player' feeling. Staffing means giving up on small things... being in the midst of it all is one of them.