What do Presbyterian, UNC-Asheville, Campbell, Samford, Jacksonville, Nicholls State, Coastal Carolina, Florida Atlantic, and St. Peter's all have in common? The title of the post gives it away -- wins over an SEC West school. On top of these losses to relative unknowns, the SEC West has added a few whopping defeats to good teams (Texas by 33 over Arkansas) and ok teams (North Texas by 20 over LSU). With the possible exception of Mississippi, the entire division has suffered these humiliations.
What gives? The SEC West during the 1980s and 1990s boasted fiercely competitive teams. Arkansas won a national championship. LSU went to Final Fours. Alabama perennially visited the Sweet 16. Auburn sent Charles Barkely and Chuck Person to the pros. The current Kenpom RPI rankings for the division are range from 50 to 229. The average rank is 119. If the division were a conference, its average index 0f 0.64 would place it 10th, between the A10 and the Missouri Valley.
While maybe more eyepopping in the SEC West, these trends extend elsewhere. The SEC East has not been immune with TN losing to Oakland and South Carolina to Furman by 16. Indiana ranks 78th with a 9-8 record now into Tom Crean's 3rd season. Oklahoma sits 135th, Oregon State 136. Even the ACC, outside of Duke, has struggled in recent years. Only the Big East has retained powerhouse status, but then again, it contains 35 teams or something like that. The "big team" struggles point to the other side of the coin of the Gonzagas and Butlers -- The Best of The Rest.
Back to "what gives?" My best guess is that the exit of elite players for the NBA at much earlier ages lops off the upper tail of the talent distribution. More of the major conference schools compete for players in the fatter part of the distribution where player differences or less (or else have elite players cycle in and out quickly.) Cycles in Conference Dominance may play a minor role. Also, the decline of the SEC in basketball may point to a renewed emphasis on the relative importance of football -- See Phil Miller's More Big Ten Expansion -- Does Basketball Matter?