Just speculation, but I think Taney may be a bit more angler friendly to access at night and that makes anglers feel a bit safer. There may not be much help on the Current at night if you are wading and get in trouble. To get to some of the best spots may require a decent hike and that makes some uneasy. I would think floaters that camp out overnight would fish it a bit, but probably don't stray that far away from home base.
And I don't mean that the Current is some super rugged remote place with poor access, it is not, but once you get away from the access at night it probably is more "rugged" and "desolate" (not the best word, but I can't think of anything else) than Taney.
And the browns, on average, are probably bigger and more accessable at Taney.
All speculation, but that is my guess.