Simple...Fr Pavone was too effective at what he was doing, making the NCCB look bad in contrast, i.e., look how much ONE SINGLE faithful priest is accomplishing while the entire US hierarchy does NOTHING effective whatsoever, principally because it is a group whose moral weight has been gutted by the group's rampant tolerance of/promotion of homosexuality (see their fatally flawed document Always Our children for proof), and institutionalized dissent from Humanae Vitae.
I hate to say this, but the sun is setting on the Roman Catholic Church here. Its the bishops' fault. They cannot tolerate the Fr Pavones telling the unadulterated truth, while they keep their silence or undercut orthodox Catholicism.