To be fair, the product on the floor isn't what it used to be back in the day. The superstars don't stick around so there isn't really a pull for the average fan outside of the big name schools.
This is somewhat true, the stacked junior and senior teams made for a better product.
I think the bigger problem is that the tournament has simply gotten so big it has made the casual fan forget about the regular season.
Ratings for the NCAAT are higher than ever. Fans are rabid for it. That said, when a team (like, say, UK in 2013-14) can lose 9-10 games in the regular season, fall out of the top 25, win no conference season/tourney title, and be assigned an 8 seed...then roll all the way to the final game, the casual fan starts to wonder why they should spend large amounts of money to view a meaningless regular season contest.
Especially when that contest is against someone like the Red Raiders who is obviously an unranked, irrelevant squad.
Obviously there are a few fan bases passionate enough that they will be there, but those are the rarities with the game in its current state.
As a side note, the NCAA could fix this. Shrink the tournament back to 16 or 32 teams, make the regular season actually matter again, and you see a spike in attendance almost immediately.