Some people like them, others don't. What's the problem? Saints' names only interest Catholics: other people don't even know about them.
As for the evil sea witch association, Disney probably chose a name that was already unpopular. They wouldn't give an evil character a name that most people like -
Olivia, for instance - because they don't do anything that isn't totally predictable. A more interesting story would give an unpleasant character either a very pretty name (in most people's opinion, based on the charts) or a very ordinary one, and let the reader/viewer work it out for themselves.