There is no excuse. Some people like to live on the edge. I know people with gas cars that don't fill up till is says empty. Makes no sense to me. In an electric vehicles case it can also damage the battery. Make an extra stop along the way for 10 minutes, stretch your legs, get a coffee hit the restroom and go. The stress is not worth it. It is best to keep the battery between 20 - 80%. When you hit 20% look for a charger.