"map of int to string"
     map   [int]   string
    
    "map of state to map of int to state"
     map   [state]   map   [int]   state

In Rich Hickey terminology, it seems people reject that it is simple (non-interwoven) because it does not strike them as easy (familiar / close to hand).

( ...Any excuse to link to this excellent presentation: http://www.infoq.com/presentations/Simple-Made-Easy )