I don't know why you'd care about a brand new test being broken overnight. It's not like you're submitting the change yet anyway. It's just leaving a breadcrumb.
I think it is a good practice to push only working code, I think it stems from this. And it has a good point - you have finished something. Sometimes if you leave something “hanging” you keep thinking about it for a while, especially when falling asleep.
its a good idea to push code before signing off, what if you get sick and someone needs to pick it up, or your computer dies. A small broken test can be fixed likely faster than reinventing the whole thing again.
Yes, you are right about the technical aspect, but my comment was about psychology. Writing test and going to sleep is abit like asking a question to your friend and waiting for answer to the morning - it might get annoying.
Have you tried it? It's actually quite refreshing since you don't need to remember what you were doing in the back of your mind. The test is there for whenever you get back to it.