Probably for the same reason that most Americans wouldn't bat an eyelash at someone naming their child
Rose,
Lily,
Robin, or numerous other word names, but would laugh at someone who named their daughter Butterfly.
Some words are generally accepted as names, some are not.

The catterpillar does all the work, but the butterfly gets all the publicity. -George Carlin
See my 21 adopted PP's in my profile!