Most of my 'circle' here in the US think of H&M along the lines of how people seemed to have felt about the D of Windsor. A somewhat sad 'used to be' who still expected to be treated as if he was of the same 'royal' status as before he stepped away. H&M are basically now just B- to C level 'celebrities' with nothing 'special' about them. But that was their choice. I'm not saying they don't have a happy marriage, aren't 'good people' personally, or that they don't do good charitable work. Just that they're rather irrelevant to US popular culture and they need to stop trying so hard to be relevant.
Yet they insist they want 'privacy'. Ok then, do your good works, attend your charitable functions, run your charitable foundations. That's what 99% of the philanthropists here do, you don't see them splashing themselves all over the papers or making documentaries about their private lives.
W&K, on the other hand, have that royal 'something' about them. Maybe it's the clothes, the jewels, and the 'ceremony' surrounding being heir to the throne. But they also seem to be rather nice people. They don't really try that hard to 'impress' us. But then they don't have to. I think there isn't the 'negative' feeling about them here because they don't cost us anything so we don't think about whether or not they're 'worth the cost'. .
As far as the alleged racism specifically directed at M goes, it's all really hearsay, isn't it? There is their truth and the RF's truth, and as with all things the 'real truth' lies somewhere in between.