Lao Xue is famous.
The first reason is relatively simple. In fact, many of us don't like trouble. If a thing is too troublesome, we may not want to do it. If it looks too troublesome, we probably don't want to touch it, and so does a star with a name. If it is too complicated, we may not listen, but if it is simpler, we may want to listen more.
The second reason is that it can express feelings better. In fact, I don't think the names of songs are many and complicated. Simple names can express emotions better, because if a song can be clearly expressed in one or two sentences, then we can better understand those emotions.
The third reason is easier to understand. In fact, I think the reason why stars name their songs casually is because it is more painful, which can let the people we listen to understand such emotions and let us feel the emotions inside.
All in all, I think the reason why singers give names to songs casually is because it sounds better.