In general, people want to trust, until that trust is broken.

TSA is really deep in the "trust" hole with the public, partly due to management/policy actions, and partly due to the behavior of individual screeners. It takes far, far longer to rebuild trust than to destroy it.

You maybe right: the public may never again trust the TSA. But that is laid upon your (the TSA's) own feet.

All the incidents of misbehavior by TSA employees have not gone unnoticed. And each incident makes it worse (or as a partner of mine used to say "you're only as good as your last screw-up"). Some trust might be restored if TSA management would not impose ludicrous policies like they did after the panties bomber, and if the would stand up, show some courage, and publicly denounce the bad actions by the workforce instead of defending those actions or hiding behind a wall of blame-placing, secrecy, or denial. Had the agency stood up with a strong statement against the overreaching screener in Fofana (instead of letting it go to court), or stood up and publicly said "the behavior of the screener in the Newark incident is intolerable and he has been fired", or said much the same in the recent Philly case, then some trust would be restored. Instead we got a full-court defense in Fofana, blame-placing in Newark, and a cover-up in Philly. The nipple-ring incident is another example.

If you want to rebuild trust, the agency has to show honesty and integrity, both of which are lacking. Not that all screeners are bad (there are plenty of good ones), but the bad ones are not smited down quickly.

For a great example of how it works, read this article. Now think how the concept applies to the TSA.