The main reason the F-16's missions are primarily air-to-ground is because nobody wants to fly against it (especially not now, with F-22 support.)
If you stop (successfully) designing aircraft to win air-to-air engagements, an opponent can focus on winning air-to-air engagements, and pretty soon it'll be their aircraft that are being used in ground attack roles ;)
If you stop (successfully) designing aircraft to win air-to-air engagements, an opponent can focus on winning air-to-air engagements, and pretty soon it'll be their aircraft that are being used in ground attack roles ;)