I don’t have much to add, except to say a few “perfumey” things:
—There are many, many different varieties of vanilla, and the way it’s collected can also have an effect on the end scent. The different vanillas have different “tones” to them, and so many people will prefer one vanilla to another, even though both are “vanillas”. Vanilla can smell like chocolate, like flowers, like bourbon, like cake…etc. It can be collected in many ways, including with alcohol (more traditional glass-bottle type perfumes) and with water and with wood smoking.
—Vanilla may be popular because it’s similar to a skin musk. Although not identical, many better-made vanillas seem to heighten that delicious skin smell, without overpowering it the way other perfumes can.
—Vanilla may be popular with women because cooking vanilla is very widely available, and comparatively less expensive than traditional perfumes. (Just conjecture on my part, really.)
As a heterosexual female, I don’t feel a traditional vanilla would smell good on a man; however, a proper smoked vanilla with a base of ooh, say, aged oak, would be very enticing.