To paraphrase Mark Twain, "the reports of the death of backpacking in the Smokies have been greatly exaggerated".
According to data collected by the National Park Service Visitor Use Statistics website, the number of backcountry overnight stays in the Smokies jumped by 37% in 2014, when compared to the prior year. Moreover, the 86,153 backcountry overnight stays recorded in 2014 ranks as the second highest count in the last 15 years.
Some people in the backpacking community thought that the sharp drop-off recorded in 2013 was a direct result of the backcountry fees that were implemented in February of that year. Although that may be true, that some backpackers were essentially boycotting the park in protest to the fees, that trend appears to have been reversed.
Here's a graphical look at backcountry overnight stay counts over the last 15 years: