There is truth to that despite the fact that on surface it makes little sense. Zizek once made this point as it relates to political correctness, how despite being ostensibly a set of norms in favor of oppressed classes in practice its something that is more commonly associated with the educated upper classes while the working class tends to be more vulgar.
So Trump's vulgarity made his seem more relatable to the working class, especially working class men, because despite having little to nothing in common with them Trump at least spoke more like them than your average politician who tends to have very polished speech.
Kind of an indictment of America that all one needs to do to be relatable as a politician is be a unapologetic vulgar asshole but it is what it is I guess.