If we regard nationalism as necessarily harmful, we end up supporting the Soviet Union, and every empire and two-bit dictator who manages to hammer together a variety of disparate groups under a single national banner.
Smaller countries have often been shown to perform better than large countries in terms of overall income and in economic growth. Also, their populations often enjoy more healthy and safe social environments.
If opponents of the current ideological winds blowing in Virginia find themselves in a permanent minority, it may very well be that the only method of defending the minority position is by leaving the state. But "exit" can theoretically be obtained in more than one way.