Yeah, I'm persuaded by your parsing of it, and furthermore, you've really clarified the thing that got my goat the most, which is that truckers... just aren't vilified? Everyone **doesn't** hate your poor, embattled, honest profession. In pop culture, the images that come to mind are maybe four-fifths rugged, cowboy-types whom we're supposed to admire (and then one-fifth skeevy unpleasant types--but come on, people! four-fifths to one fifth!) The sticker was so unexpectedly and wrong-headedly hostile/defensive as to provoke bewilderment and confusion rather than the probably desired angry-owned-lib reaction.

Kind of as if you saw a sticker saying "Don't like bluebirds? Then don't build all those bluebird houses!!!" ... Well, maybe that's overselling the innocuousness or beloved-ness of truckers, but I felt a similar ??? when first reading the sticker.