Both Eyes Fixed

What is it with people in Canada? You ask someone if they're free to do something three weeks from now, and they say, "I don't know, I'm not sure what's going on that day." The ideal thing that would follow would be to check and find out. But that never happens, and they don't get back to you. They really don't want to commit in case something better comes along between now and then. That's fine if you don't really want to do something, but why not just come forward and say so? Why beat around the bush with a misleading "I don't know my schedule" remark, if you're not planning on knowing your schedule? It's almost as if you're being "stood up" ahead of time.