There’s two aspects of this story:
First, God called Thaddeus and Kristen personally to plant a church in Charlotte. You can watch their video on discerning a location here. Briefly, they entered a four month process of discernment for a location. Over those four months, God birthed and grew a love for Charlotte that truly made even the most attractive cities in Orange County pale in comparison.
Second, in the last few years Charlotte has been one of the top five fastest growing cities in the nation. It is the largest city in North Carolina, and continues to grow in population and influence. Planting churches in cities like Charlotte creates an upward cycle of influence. A new church plant revitalizes existing established churches by presenting new ideas, new systems and reaching new people. This in turn creates gospel renewal in those existing churches. This gospel renewal then catalyzes the existing churches to plant additional churches in the area and in other places, repeating the cycle indefinitely.
If you’re curious why someone would want to plant a church, read this resource published by Tim Keller – Why Plant Churches?