Mine: Embrace the Spos' legacy.
For me, it's a "why not, who doesn't want their franchise to be associated with names like Dawson, Carter, Martinez (both Dennis and Pedro), Wallach, Walker, Staub, Guerrero, and Raines."
For others.. not all, but more than I'd expected... it's seemed there's an attitude that says "this is our DC area team, period, so don't be muddying our territory."