I’m uncomfortable with people that have a rigid separation between “people I want to fuck” and “other” and have widely different approaches to dealing with the two types. If you only approach strangers that look like you might fuck them, and besides that you never strike up conversations, that seems to indicate that you don’t really like people, you just like fucking. If I’m the one you are approaching in this way, I feel like you don’t really like me, either, and if I didn’t happen to qualify as potentially fuckable, you wouldn’t give me the time of day. In fact, if in the course of our conversation you decide I’m not fuckable, you’ll leave, which will make me feel pretty shitty.
So I guess I feel like extroverts who like people have a lot more license to chat up people they are attracted to, because they chat up people all the time. So if you talk to people at the nude beach, you can talk to pretty girls at the nude beach, and if you hit it off you can ask her out. But if you ignored everyone too old, too young, too obviously in a relationship, or not your physical type, it’s really obvious that your appearance of interest in a person is really an interest in sex. And that will make a person uncomfortable.