Nashville is not like New York or Atlanta where it attracts young ambitious single people.
That's one way Nashville is not like Dallas. A lot of single people who move to Dallas are ambitious. One of the big selling points of moving to Dallas are the corporate job opportunities in the area. That attracts both the unmarried and unattached people and the married people.
Your typical person moving to Nashville is married or already has a social circle established there.
Many of the recent arrivals to the Dallas area (last 10-15 years) have been already married people moving to a Dallas suburb like Plano, Frisco, McKinney, or Allen. The people who move to Dallas proper are usually unmarried. Some of the unmarrieds are unattached while others who move to Dallas itself are unmarrieds with girlfriends.
I think it is easier to move to a new city while married. I do think this audience of relocating marrieds eventually runs into trouble in that city when the marriage ends, though in many cases that's 5+ years into the future. Marriages do have a track record of ending. Also, this audience when they do reach the dating market, they are reaching the dating market as older single parents. I'm not really plugged into that audience.
It's difficult to be a person moving to Nashville and already have a social circle established there. The only way I see that it is possible is if the recent relocatee previously lived in Nashville, especially during childhood or already has similarly aged family members (like cousins) there. Please explain how someone can move to a city and already have an established social circle.
Nashville is one of the hardest cities to build a social circle. Most of the single people I know that moved to Nashville ended up hating it and moving back lol. But this depends on where he is from and his character.
Let's say there is a 25-35 year old unattached, childless male moving to a city. If he moves to Nashville with no social circle in place and knowing almost no one, he'll have to make friends and find girlfriends based entirely on his own efforts. It seems like guys in that position have a difficult time doing that in Nashville. While that task is difficult in most major US metros, it seems like you're saying doing that in Nashville is more difficult than the average US metro area.