There is an option to do that today. You can add a bottom track and fill it with a black Color clip. Maybe you would call that a “workaround for a GUI problem”. But we do not want to burden all projects with the extra overhead of having an extra track that most people do not use/need.
As a convenience, you can make a template project that has the bottom black track and then always start new projects from that template. I think may people keep a template project to reuse various features that they personally find useful.