People who eat milk chocolate as a matter of preference are not particularily passionate about it. I mean, they don't have to have something special or specific. Chocolate in general (which is usually milk) will suit them fine.
Those of us who prefer dark chocolate can be a damn sight more picky. Not just ANYTHING that says it's dark chocolate will necessarily work. I've had a lot of pseudo-dark chocolate in my life and it is always a DISAPPOINTMENT. It just doesn't really qualify.
Dark chocolate lovers are going for a very special flavor experience. I'm constantly looking for the absolute perfect dark chocolate -- just this side of really bitter and dry, mostly pure chocolate liquer, just that absolute creamy, warm, tingly, sensuous experience. Mmmmm...
Oh, yeah, right....anyway, milk chocolate people don't seem to get that passionate, at least not the ones I've known. They don't pick through the entire box for the 3 dark chocolates, rejecting the rest as "just not good enough". They know the names of less well known European chocolatiers. They know there is a bean involved and that beans grown in different climates create different chocolates.
In fact, they are a lot like gourmet coffee lovers. Only fatter. Slightly.
They also may have lower bloodpressure.
AS for so-called "white chocolate" -- it has NO CHOCOLATE IN IT. It's just cocoa butter, vanilla and sugar. Why isn't is called "Vanilla"? Feh! Feh feh feh.