I believe it became popular since the traditional Jewish symbol, the seven-arm menorah, was considered “too Jewish”. A “lion” might be more appropriate for Eretz Yisrael, but the current regime wouldn’t want to remind people that they are usurpers by using the seal of the royal house (which could easily have been represented by a regency if a Jewish state was ever established there).
Six pointed stars are common in many cultures iconography. American police often wear them. They almost ended up in the American flag.