Could you at least answer who you believe they are supposed to be targeting if not people who set off explosive detectors and can't provide concrete evidence of anything they say?
Thousands of people in the U.S. fly without business cards or ID listing their current addresses. University students are just one obvious example. This simply isn't uncommon. If you want to target that, you might as well target retirees or snowbirds. Of course, you wouldn't, since you profile based on demographics, ethnicity, etc, in addition to merely not having a current piece of ID or a work phone number.
Explosive detector results, sure. So determine it was a false positive and let them go. It doesn't take 3.5 hours to verify a person and their bag don't have any actual explosives on them. The amount of questioning was not warranted.
