Marquette v WKU.
I've been to 8-10 ncaa tournaments. Its such a male dominanted event. More than any other.
If you think about trip planning this kinda makes sense. Compare to a bowl game:
Most Bowl games I've been to have been as a couple with my wife or previously girlfriend at the time. Even if the woman just detests sports, the game in only 3.5-4 hours and she gets a trip to a fun destination out of the deal.
With NCAA Tournament games there is a LOT more time devoted to the sport and the destinations generally aren't as nice. So, when I went to the F4 it was a "boys trip".
Another factor, planning:
When you are following a team, you have almost a month to plan a bowl trip (not including CFP games beyond the first round obviously). That is long enough to plan a couples or even a family vacation around the game.
With NCAA games (if you are following a team) you have just a few days to plan the trip. You find out Sunday that your team is playing on Thursday or Friday and where.
When my buddy and I went to the F4 we didn't know the Buckeyes would be in it until (IIRC) Sunday when they won their E8 game, then left five days later on Friday for Atlanta.
You can do that with your buddies because if you wind up in a crappy hotel you can deal with it. That is a tougher sell to a wife or g/f.