I was watching Minn-Purdue today. Purdue was down by 13 at home in the second half, went on a 21-2 run and won by ten. They did it mostly by playing aggressive -- going to the hoop instead of chucking up threes, and playing in-your-face defense. It was a stark contrast to what Ohio has been doing this year.
I'm not sure what you think you saw, but Purdue is literally 15th in the nation in 3s as % of overall points. They shoot the 22nd most 3s in the nation.
For comparison we are 266th in the nation for 3's attempted.
Our defense has been very good, 72nd in the nation. 2012 is literally the only year we've had a better defensive team since kenpom started tracking tempo-free defense in 2002.
I think it's taking the easy way out to say "we don't play tough defense" or things like that.
At the end of the day basketball is about shooting the ball, and our team is historically inept in that area. That's what it comes down to.