Nothing against VA, but isn’t it pretty high up in latitude compared to Southern Florida?
The reason Cape Canaveral was set up down there was to take advantage of the additional speed gained by getting closer to the equator.
Maybe VA offers other cost advantages make up for the extra-strong rocket needed compared to a more southernly launch….
Part of the reason for Orbital picking Virginia is that it’s less crowded than Cape Canaveral. They would have to compete with other companies, who have been there for much longer, for launch windows and real estate.