> Connecting two occupied points is the exact opposite of building a road to nowhere.

I'm at a loss as to why you even bought it up. My intial comment here:

     roads | train lines built to connect A and B will often be followed by small townsites along the way and the spread of "off the grid" living at blocks T junctioning dirt road access from the new A <--> B route.

was about development following roads that connect places and that development expanding outwards into what was once "nowhere".