The reason all bi women are crazy is that all the women that go around people they are bi are the crazy ones (no matter if they are actually bi or not), not bi women in general. They do this maye to seem more interesting, progressive, etc, when it's just retarded and nobody cares.
If you are single there's no use in telling people, because you are by (lol) yourself, and if you are taken, then youve Already chosen someone to be with, so its equally useless unless you are a cheater or something
youve very likely come across bisexual women and never knew because the topic never came up or they didn't feel the need to mention it