The worst teams over the last 10 years seem to show a few things:
--5 of the 10 worst programs over that period are from the midwest (Indiana, Purdue, Illinois, Iowa State, Kansas). Population growth is not keeping up in the midwest and the result might be reflected in all these bad teams. The bottom tier programs in the region have especially slim pickings to recruit from and are suffering as a result.
--the ACC is well-represented near the bottom: 4 of the teams from 11th to 20th worst are from that conference (Wake Forest, Virginia, North Carolina, NC State) and another one, Maryland, was in that conference until last year. Three more teams are in the next worst group of ten.
--Northwestern and Minnesota are also in the group from 11th to 20th worst. That makes 5 Big Ten teams among the 20 worst in the last decade. The Big Ten is becoming very much a conference of Haves and Have Nots with a small middle class (at this point probably Iowa and Rutgers and maybe Maryland). Hopefully our geography will help us avoid the downward spiral seemingly afflicting so many other Big Ten teams.
--Unsurprisingly the SEC dominates the Top 10 with 4 teams, but falls off after that. It's even more of a conference of Haves and Have Nots than the Big Ten, only the SEC's Have Nots are not quite as poor as those from the Big Ten.
--the PAC 12 is not particularly the 2nd best conference over the last 10 years. Oregon and USC appear in the Top 10 and then no other programs appear until Stanford and Arizona State at 24 and 25, and newcomer Utah at 26. The Big Ten has the same number of teams in the Top 30, and newcomer Nebraska at 20. And Michigan stumbled during the last 10 years but that has probably come to an end.