billionaires are literally a minority group. they certainly don't need protected status, but, whether or not it is "good" to take their money, they can't effectively oppose this just by voting.
The argument for preventing one person to amass that much wealth is at least in part that it gives them tremendous political influence. The preferences of Sheldon Adelson arte far more consequential than an average voter living in the same district, for instance. Appropriating the language of "minority" discrimination, which traditionally refers to marginalized groups, to talk about people who are very rich strikes me as distasteful.
one could just as easily make the argument that academics and social theorists have appropriated a word that has a commonly understood statistical meaning. no one objects to calling the alawites of syria a "minority group", even though they are relatively privileged and literally control the country. especially in the context of a (putative) democracy, it makes sense to use the word in the statistical sense.
Nonetheless, most of us would agree that some abridgement of rights is acceptable for this "minority group." This is why I don't think talking this way is helpful.
