When a point is moot, it's too trivial to think about. If your basketball team loses by 40 points, the bad call by the official in the first quarter is moot: it isn't important.
Though moot can mean to debate endlessly without any clear decision or to think about something carefully, it most often describes ideas and arguments that don't really matter. If your plane is crashing, whether or not your socks match is a moot point. When someone accuses you of making a moot point, he's basically saying, "Come on! Let's talk about what's important." As with so many things, people don't always agree on what's moot and what's not.