My take is that it's a perception thing: If the Vols had been kicking a$$ the last couple/few years, this kid probably would have committed--fearing that he's going to miss the Vol locomotive chugging down the track. When your muddling along, kids are more inclined to look around.
Nebraska is different and can't be compared to UT, in my opinion. There is NOTHING going on in Nebraska or that part of the country--very few if any good programs in neighboring states. So if you're a decent football player in that state--B level, not top 100 or 200, meaning teams aren't beating down your door, you want that nebraska schollie even if the program as suxed for 10 years.