Question: I'm looking for something people from rural area would use, especially when they refer to that person's inability to adapt to the country life.

Answer: 
[Townie](http://www.collinsdictionary.com/dictionary/english/townie) is the obvious answer, but *tourist* or *tripper* often carry overtones of scorn and 'urban, squat and full of guile'. (I knew a young girl who, left in a car for half an hour, hid under the seat because she was afraid of the trippers.)
(D\*\*ned) urbanites. Or if the rural area happens to be hilly or mountainous, flatlanders.