And regarding "lacking creativity to create own believable cities" why reinvent the wheel?
Because that's where the money's at? yes there is that argument of, why can't GTA look as good as PGR4?
Doesn't it? It'll happen one day though, infact, you're going to start seeing random city generators soon, that will generate an entire city for you based on simple basic instructions.
I wrote one of those in Blitz3D. Worked fairly well, considering the language it was written in.