I disagree, in my understanding GE is more about security and less about customs. GE is only available to citizens of select countries who exchange info about their citizens with US authorities.
You may not be eligible for participation in the Global Entry program if you:
* Provide false or incomplete information on the application;
* Have been convicted of any criminal offense or have pending criminal charges or outstanding warrants (to include driving under the influence);
* Have been found in violation of any customs, immigration or agriculture regulations or laws in any country;
* Are the subject of an ongoing investigation by any federal, state or local law enforcement agency;
Have been denied for the purchase of a firearm;
* Are inadmissible to the United States under immigration regulation, including applicants with approved waivers of inadmissibility or parole documentation; or
* Cannot satisfy CBP of your low-risk status.
As you can see, at least 3 or 4 items in the list are about security and only 1 item is about breaking customs / agriculture regulations.
The background checks is the big part of getting approval.
Source: https://www.cbp.gov/travel/trusted-traveler-programs/global-entry/eligibility
I'm a strong believer, travel to countries like Syria, Iran, North Korea, Cuba and others significantly reduce chances of getting or keeping GE membership.