Why would I want/need a revolver chambered for a rimless cartridge? Why not just get .38/.357?
As a civilian, I personally have never felt the need to carry a "BUG", so ammo commonality with a primary weapon is a non-issue. I suppose this could be a consideration for LEOs and/or really gung-ho CCW civilians.
Is it a monetary thing, so that you can buy ammo in bulk (thus presumably cheaper) for use in multiple weapons? I already weapons in a variety of calibers, so I don't think I'd see much savings, since standardizing on one caliber is not going to happen.
Are there advantages I have failed to consider? I mean this question sincerely, not intending to stir up debate.