Global Entry means that you get favorable treatment and less stringent screening at customs in exchange for doing the interviews and background checks to become a trusted traveler. But that only works if there is high confidence that those trusted travelers aren't violating the law with that lax screening. They have to issue strict penalties for non-compliance otherwise they can't give those trusted travelers less stringent screening.

It makes it harder for all the other GE members when people break the law as a GE member.