Generalizations pertaining to the visual appeal of the residence, showing, size, condition, etc., are typical of any market and probably has a significant affect on why he is unable to sell his property.
All homes are not created equal. A lot will depend on square footage, location within your neighborhood, amount of updating and quality of updates, floor plan and flow of home, size of lot, etc. Is it easy to show for the agents? Is it staged properly and shows well?
Your best bet is to have an agent or several agents give you a detailed assessment of your home in comparison to your neighborhood. Please feel free to call email me or any of the agents who have answered here and we would be glad to help.
I sell from Oak Cliff to Frisco and having lived in the area over 27 years know it well.