The only explanation I can offer is that it points to the powerful lobby of the major D1 football coaches and ADs.
The Coaches Associations of the various sports play a big role in this I believe.
Also, the tide may be gradually turning. Division I wrestling now has an exception that's available only in a wrestler's freshman year with a D1 program. Division II football also now has a rule somewhat like D1, but it's limited to 3 games in a D2 football athlete's freshman year only.