The problem is that the Capitol Riots represent the extreme 1/2 of ALL America. Not just the ones below the mason Dixon. ALL America. That suggests 1/2 the capitol police (and seemingly the few in prominent leadership roles) saw this as that rowdy kin coming over for dinner. Obnoxious, but they’re kin and harmless.
I think it shocked them when they realized the “movement” they believed in contained the same flaws they where belligerently screaming was wrong with the “other side”. No one wants to see that touchy feely uncle Larry is actually the same monster as the Larry guy that’s now in jail for rape.
They had blinders on and they where rudely awakened.