Facebook is really sh***y like that.
Firstly because it's a vehicle for people to be super fake and shallow. If you have 200 friends, probably only about 5 of them are really friends, in the sense that they will put themselves out to help you.
Secondly because it has its own weird rules that most people don't understand. For example, if you have 200 friends, it's quite possible that Facebook only decided to show your post to 1/4 of them, so lots of people won't even have seen what you posted unless they were looking on your page, which many people don't do.
Thirdly because people don't always know what you mean online. So presuming a 'friend' was lucky enough to see your post, and she happened to be one of the 5 people who are your real friends, she might not know whether you were serious or making some kind of joke. She might not know who you meant. Or she might not want to respond simply because nobody else has. Or any number of things.
Probably if you want to meet up and do something, instead of making a general status update post, pick out several people you feel that you are actually reasonably close to, and message them directly. That way you know they are likely to read your message. Also if your friend gets something specifically for her, she will know she is meant to respond.