Ok, dammit, I got sucked in and looked it up. Here is the list of coaches in the top-8 leagues (ACC, American, A10, Big 10, Big 12, Big East, SEC, Pac 12) who are in at least their fifth season at their current schools and have not made the NCAAs during that time. There are 100 teams in those 8 conferences and there are 9 coaches who fit this criteria. I'm organizing them by longest tenure at their current schools:
• Lorenzo Romar, Washington, 14th year, last made NCAAs in 2011, two NITs since then
• Chris Mooney, Richmond, 11th year, last made NCAAs 2011, one NIT since then
• Ed Conroy, Tulane, sixth year, no NCAAs, no NITs
• Jeff Lebo, sixth year at ECU, no NCAAs, no NITs (they were coming off 14 straight losing seasons when he was hired)
• Kevin Willard, Seton Hall, sixth year, no NCAAs, one NIT
• Donnie Jones, UCF, sixth year, no NCAAs, one NIT
• Brad Brownell, Clemson, sixth year, last made NCAAs in 2011, one NIT since then
• Pat Chambers, Penn State, fifth year, no NCAAs, no NITs
• Billy Kennedy, Texas A&M, fifth year, no NCAAs, one NIT