Just because you've successfully created a wildly successful business, does that imply that you should now also be the person to decide how all that money is spent? Why would society agree to this? We can acknowledge that you might be a brilliant business person without simultaneously and implicitly agreeing that you're just the smartest person around and should clearly get to control where all that revenue flows to.

Hence, the 1950s & 1960s idea of taxation: you can earn boatloads of cash, but we'll tax a lot of it away from you. You'll still have enough to be crazy rich and lead a life everybody else can only dream of, but you're not going to control the disposition of (say) US$20B.