Most Helpful Girl
Totally honest truth:
Sex with a man you love is always significantly better than with a man you don't love. However, there is some truth to what you're saying. Despite what our culture tries to portray, women crave sex and intimacy a lot as well. Due to the fact that men tend to think of women as "sluts/whores" and won't take her seriously for a relationship if she has sex too fast, she MAY choose to give it up quicker for the guys she doesn't want a relationship with. She figures she's not losing out on anything.
This is tough for guys to understand because we don't judge you regardless. We still take you just as seriously for a relationship regardless of how quickly we have sex. Because men tend to view us differently, we treat it differently based on how much we like the guy or how much of relationship material we see him.
Sometimes it does have to do with immediate attraction. A lot of women get into relationships with men whom they weren't initially attracted to, but they were good guys, and attraction developed. The ONS often happen with guys who spark that intense sexual attraction very quickly.