It isn’t a dog whistle. The US actually does have a high-trust society compared to most of the world. Petty theft, snatching, pickpockets, scams, etc are relatively uncommon compared to e.g. many popular places in Europe. Americans are famously vulnerable to it when traveling because it isn’t really part of their domestic threat environment. In many areas, Americans don’t bother to lock anything. You can leave stuff out in public places and it is unlikely to be stolen.

I would say it is lower trust today than when I was a child. Some cities have developed real petty theft problems due to disinterested enforcement. It is still noticeably higher trust than most places in the world I’ve traveled.