D2 was a true division with historical rivalries and a relatively even playing field that still promoted the best programs to rise to the top.
FCS is just D2 with a few more scholarships minus all the regional schools that were small but actually cared about football. The mad rush from D2 to FCS was predicated on buy games from the Big 10 and others to pay for their football and athletic budget.
This is indeed very bad for FCS schools...but it serves them right for their dumb desire to join up just so they could be paid to lose. They used to have honor...now they have nothing.