Destiny has made a huge ammount of money, but D1 didn't sell 30M units. It amassed 30M registered users over three years, which includes tons of siblings, roommates, romantic partners and spouses playing on the same copy sold. D1's sales were probably somewhere around 20M, give or take. There's a reason they make registered user numbers public and not sales, so that people like you will believe and state that sales were even higher than they were.