If the ticket was an all session one (both days) you were counted Saturday and Sunday. If it was a single day pass, you are counted for that day only. There are a whole bunch of Notre Dame fans (myself among them) who will be counted in today's crowd that won't be anywhere near the Huntington Center.
Also you could not draw 6000 at most campus sites. Half the arenas in the NCAA hold fewer than 4000, with many in the 2000 range. 35 total hold fewer than 5000 and only 10 hold 6000 or more. Even Yost holds fewer than 6000 after their latest renovation.
This year 2 of the top 8 (Quin and Miami) and last year 3 (Union, Ferris and Miami again) have rinks that seat far fewer than 4000. With some schools on break, Easter, or who knows what other excuses many of the first round games would occur with students sparse in numbers. I'm not saying home ice for top seeds wouldn't be a better environment (obviously it would be), I'm just noting that it would hardly mean large sellout crowds of 5 or 6000 or more at every game.
FWIW, I do believe the absolutely horrendous crowd in Grand Rapids, despite the presence of two of the sports most marquee schools, is going to be the death knell for the regional system as we see it now. Notre Dame's voice carries a lot of weight in college sports and right now that voice is pushing for a return to campus sites for early round games.
Locations and arenas have not be awarded for 2015 yet, and I look for the tourney to return to campus sites for the 1st round and quarters in a best two of three format, similar to what we had from 1989 through 1992. Look for the griping about the PWR to be ratcheted up even further among teams seeded around 9th-12th. People complain heavily about having to face a 2 seed they think is demonstrably weaker than they are despite the PWR. Imagine what folks will be saying when they have to face that team on their own ice instead of a neutral surface 200 miles from their campus.