Wonder why calling an older girl/woman 'cool' is a turn off for them? What do they want to be called, then? Cute? Beautiful? Sophisticated? That they look stupid for having something stuck in their teeth?
I think the book summed it up. You could say it to
anyone. It doesn't have much to do with them as a person and is superficial. It's better than "you have a nice ass" though.
Exactly this, yes. Technically all those other words can apply, as well. You could call just about anyone such simple words on their own. Conveying feelings is tough, as you'd have to communicate just what you like about the other person, and how.
At least 'sophisticated' gives off a more specific vibe, though. And sometimes 'cute' and 'beautiful' can work, given the right context, I figure. But 'cool' really is such a generic term with so many ways to interpret it that vary between individuals. Though the aforementioned terms of attractiveness have the same pitfall. After all, beauty is in the eye of the beholder. But it does strike closer to the heart of the matter, of course: being attracted to them.