It's more common in England.
http://en.wikipedia.org/wiki/Hermione I believe one of these Hermiones was in
Mary Poppins, and another in
Gigi. Since
Hermione Granger is a hero in the HP series, I don't see that as a huge negative point.
Bellatrix,
Lucius, and
Severus on the other hand have negative conotations. (I know,
Severus's story has a twist just before he died and is redeemed, but he's still a bad guy for most of the series.) If you really don't want the comments, then use it as a mn. If you love it enough to use it as a fn, go ahead.