I know for a fact this isn't true. These kids are bigger fans than you think. I know. So its not a legitimate reason.
You know for a "fact" that the "opinion" of 17 & 18 year old kids in West TN is that UT is favored in comparison to Ole Miss, Arkansas, MSU, and Tiger High?
So...you've polled high school athletes in West TN, specifically Memphis?
West TN in general is pro-UT, but there is also a LARGE contingent of Ole Miss fans, a not so small group of State fans, and decent size population of Arkansas & Tiger High fans (specifically in Memphis).
I didn't realize just how diverse Memphis was, in terms of college loyalty, until about 5 years ago when I began working out there. I'd go so far to say that Ole Miss, UT, and Memphis all vie for the loyalties of the city and could either be in a three-way tie or change from first to third, depending on the time of the day.
Say what you want, as a whole, UT owns the lion's share of West TN but Memphis is the exception....and outside of ATL, it's likely the most diverse city in terms of team loyalty in the South.