Sorry about the link. It is to a website where you filter for the $ data you want. This is the site,
http://ope.ed.gov/athletics/index.aspx
That should get you there and then you can look for whatever you want. I filtered for D1 schools and searched for aggregate #'s since everything's divided differently between the two sports, football revenue roughly $2.9 billion, basketball, $1 billion. Adding in the tourney takes that number to $1.7 which is pretty doggone close to the split you just referenced.
No one's saying it isn't important. Well I'm not anyway. But it isn't on footballs level. A 60/40 split amounts to huge dollars at this level. To say that college basketball is as big as college football just isn't true, hence secondary. To say that it isn't big in it's own right would also not be true. Otherwise the schools like KU and Indiana and Duke, etc that don't give a crap about football wouldn't be able to afford to do so. Which we all know ain't the case.