You don't want just the CC holders OCing. I would think you would want non-CC holders OCing as well. You don't want to poach from your current pool of carrying people. You want to make that pool of carrying people LARGER!
The 2nd Amendment doesn't pick sides. Why should we? It only talks about 'carrying', not OC or CC.
We need everyone to OC or CC according to their needs & preferences.
But yes, it is good to see progress.