Is it in bad taste to dress as real people for Halloween?

I’ll actually need a Halloween costume this year. In the past I’ve put together last minute costumes that were either generic, or were made from cardboard boxes. I’ve narrowed it down to a few options, one of which being Isadora Duncan. I really liked that idea, but I’ve never dressed up as a real person, and I’m a little bit conflicted about it. So, what do you guys think?