I believe your are correct. Cruiser were just small battleships and just as unnecessary for modern warfare.
Cruisers and the new Zumwalt class DDG are not built for surface ship to surface ship warfare, although they are certainly capable of defeating virtually any surface ship in that kind of engagement. They are built for sea control, anti-air, and anti submarine warfare. And their prime reason for existing is protection and support or carrier battlegroups.
Cruiser Command.. when you can billet an officer to command a Carrier but want them to advance higher than a DDG. You are probably done advancing when you are assigned command of a cruiser.