BC does not drive ratings. BC gets good ratings when they play a school that drives ratings and they are on ABC or ESPN. Last year, four of BC's football games were on the ACCN, 1 was on CBSSN, and 1 was on The CW. If they were a ratings driving team, you would have seen them more on ABC or ESPN as the networks understand what schools drive ratings. Their highest rated game was against FSU on ABC, both of which are ratings enhancers.
This is why FSU wants out of the ACC. If schools like BC, Wake, Duke drove higher football TV ratings, the media contract would be much better for the ACC.