Why cantrips like booming blade and green fire blade aren’t in the PHB?

@DanDanisepicI’m relatively new to dnd and I wanted to know why cantrips like booming blade and green fire blade aren’t in the PH We designed those cantrips well after the release of the Player's Handbook. They're optional.

— Jeremy Crawford (@JeremyECrawford) July 5, 2016