The reason why many people are indirect is because it helps reduce conflict and awkwardness. For instance, let's say a woman is interested in you. If she just asks you out and you turn her down, then she feels hurt and the conversation becomes very awkward. But if she hints at you that she is interested, then if you want to ask her out you can, but if you don't want to ask her out, you don't have to explicitly reject her. This avoids hurting her feelings and making the conversation grind to an awkward halt.
Or let's say you are doing a behavior that someone finds offensive. If they tell you "Hey, stop this behavior, I find it offensive", it might embarrass you in front of the other people there, or you might get offended back, or you might feel hurt or ashamed. But if they are able to hint at you to change your behavior in a subtle way, then you get to save face and the awkwardness is avoided.
A final reason is that having some ambiguity makes the interaction more fun. If a girl tells you "Please kiss me" and then you do, the kiss might be enjoyable but you are just doing what she asked, and that's not very exciting. If instead she subtly signals you to kiss her, then there is still much more ambiguity and suspense. Then when you finally do kiss her, it's more exciting.
Of course, this is a very frustrating system for folks with AS. But if you learn to pick up these subtle signals, you can find yourself having much better social interactions
Remember these subtle signals are here for a reason and instead of opposing the system, try to work with it and make it work for you.