Well, me personally, I don't know if I'm alone in this or not, but I rarely create my own girls. I usually take girls from others' creations, as if in real life - meeting a real, never before seen girl, not even knowing her name, like a first date or something
AND I prefer those nice beautiful girls to have their "own" names, rather than giving them names myself, or rather than just being named HATANO MIWA.
Similarly, if I decide to create AND share a girl of my own, I will definitely give her a name. I don't know, sounds more "complete" by giving them names