1 game demotions

Why does demotion happen one game after getting 0 lp? no grace period or anything? Once you get demoted you have to win about 4 games to get back to where you were... this means that for losing 1 game at 0 lp you're treated to a 4 win minimum punishment which makes no sense, especially if you keep getting back to where you were and then suddenly winning is no longer an option despite not doing badly usually. Guess I have to look for 4 other players and just take advantage of the new ranked system since playing alone is pretty much high risk low reward.