...it is far too tempting for two people to get physical early on and spend less time talking and getting to know eachother. Basically you end up with a sexual relationship, but when she or he doesn't match your sexual desires the relationship fails.
What it sounds like you're saying here is a version of your not being 'sexually compatible'. That would seem like something you'd be more likely to discover only after you actually started getting physical. Wouldn't it?
I know how it feels to invest a couple months in someone...only to realize it isn't right. I think sometimes it just takes that time to really start getting to know someone and realize they aren't right for you.