I saw someone classifying loyalty the other day in a way that I thought was very interesting. They argue that loyalty is best understood as a spectrum.

(Least) Employer - location - home/community - friends - family (Most)

The most friction occurs between people who classify something at a different loyalty level. (ie saying you are disloyal to a city if you leave). In this scenario the city for Person A is a location loyalty while for Person B it is at home/community.

There is another interesting framework that you can look through to better understand why people leave cities .