WHY WE USE A STARTER SCRAP...

Because if we start sewing without one, and don't realize right away that the thread ends have been sucked away from the sewing area, then we are either sewing nothing and/or creating an increasingly large knot of thread under the needle, that jams the bobbin case and that we can't even see until after unscrewing and removing several parts.
Penalty for not paying attention: 15 minutes-2 hours, if I can fix it myself (please oh please let me be able to fix it myself)...