Well I'm not the only one who's said it. Pretty much anyone I've spoken to who's got those particular tyres on their truck has been disappointed with their performance on wet and/or muddy surfaces.
I think I'm inclined to agree with the tyre dealer: People buy them because they look cool. Most of those people probably only go off road when they park on the pavement. So that's basically what they're designed and sold for.
Mine are good tbh Tim - and mine really really get used