It's cool I don't mind answering questions so long as they're not hugely judgemental, which I don't think you're being.
Jazzykinks probably has stuff to say on the subject as well.
If I think someone is fit and they indicate they want to have sex with me I will say yes unless any of the following apply: they're unsuitable (eg in a closed relationship - it freaks me out when taken monogamous people hit on me, it's like WTF ARE YOU DOING THIS IS WRONG), the context is bad - I wouldn't shag a work person - I'm busy with school and don't have time, there isn't a suitable venue available (ie we both live with our parents), or I just thnl they're not a good person. I stopped sleeping with someone relatively recently because even though he's hot and good in bed, I don't like the way he talks about women or his sexual partners; he refers to the women he meets in clubs as "club sluts".
In reality, at least one of the above applies probably a majority of the time.
How many attractive guys do I see? TBH I'm not sure most of the time I'm just doing stuff and not worrying about how attractive people are. It's a hard question to answer because so much of what I find attractive is bound up in what I know of someone's personality and/or what I know of their kinks and how they like to play (I'm into the fetish scene which complicates things).
If I'm at a club, I am normally willing to at least talk to and possibly make out the the majority of the people there (I say people because I'm bi so women attract me as well). I find that after that first kiss, there's normally either a sexual tension or there...isn't.
I would also be friendly and nice to a hook up I saw out and about; always smile and say hi, just as I would with any other person I've had pleasant but not hugely important contact with, like someone I worked with once or someone who was in the year below me at school.
Unless they were really horrible to me - which in fairness not many people are - in which case I tend to avoid them and hope they don't notice me.