Oscar judges the State Science Fair and offers commentary
There's also the fact that it's contextual.
As in "normally I like aggressive men, but not today for X, Y and Z".
It's the fatal flaw of the PUA on a personal scale -- people aren't machines, whose levers can get flicked for predictable responses. Just as there is no "All women like X" ruleset that a PUA can really use, even individual people are going to vary day to day.
The plain truth of the matter is you might be a perfect fit for someone, 10 days out of 12, and you picked the day she just wanted a few drinks to calm down from a crap day at work to approach her. She just wasn't feeling it that day.
But you're right that most people don't put too much thought into it. They like what they like, when they like it. And don't when they don't. And if you ask them to describe their type, a lot of them can't really say what they're looking for. That doesn't mean they don't have something pretty specific in mind, though.