It's both, quite frankly. There are 9 players from the metro this year with a Big Ten offer, increased in large part due to the amount of scholarships Kill has had to offer, and the degree to which he's been willing to offer them to marginal local kids (Duke, Ben). In the years before it's been:
2011: 6
2010: 9
2009: 6
2008: 10
2007: 11
That's ok, but a metro area like Cleveland, Cincinnati, or Indianapolis which, by themselves, are smaller than the Twin Cities, can expect to produce 15-20 Big Ten football players a year.