Just from this year:
Illinois over Charleston Southern, 44-0
Purdue over Eastern Kentucky, 48-6
Minnesota over New Hampshire, 44-7
Northwestern over South Dakota, 38-7
Nebraska over Idaho State, 73-7
These are the games that the Big Ten wants to eliminate. There are 127 teams in the FCS and most of them will provide an extremely uncompetitive game against a Big Ten team that fans have little interest in. Obviously, there are a few very good teams in the FCS such as NDSU that would provide somewhat of a challenge to some Big Ten teams, but these games typically don't interest the fans too much. NDSU is not your average FCS team, so quit using them to try to prove a point about the entire FCS. For every NDSU or Sam Houston St that might provide a competitive game, there is a
Nicholls State or
Savannah State ready to lose 84-0.