I believe it might be related to the firing of Larry Hunter, an Athens favorite! At the time, I heard a number of people say they'd never go to another Ohio BB game.
I was going to post sarcastically that half or more of these folks were kin to Larry, who has extended family -- cousins, 1st, 2nd, 3rd, etc. -- all over the county. His family was one of the pioneer families in Athens County, and I believe that Ohio University's first graduate, John Hunter, was an ancestor. Tom Ewing was actually the second graduate, contrary to many university news release to the contrary. It was a two person graduating class, and Hunter had the better grades so he technically graduated first, as was the custom in those days.
Seriously, though, your point is well taken. I think the new AD would be wise to institute a marketing campaign to entice these folks back. As Alan points out, it's difficult, but it might be worth the effort. Somewhere the AD's office must have a list of the folks who quit buying season's tickets at about that time. Or such a list could be generated via a little research. A directed mailing to them, with some kind of a special one-time offer for former season ticket holders, might entice some of them back. It might be pointed out that our new coach is the first alumnus in the position since Larry Hunter, that might appeal to them. Just a random thought or two meant to be constructive.