Yes, I agree, your arguments are convincing. In theory, it is possible to create such a generator, but in practice... to look for a needle in a haystack. Since it is incredibly difficult to calculate the generation grain.
And yes, you correctly noticed, if such a generator manages to pick up a code, it will substitute the person to whom this code was issued. The account of such a person will be banned, his subscription will be canceled. It's unfair. For this reason, I remain a supporter of the hacking option. A small modification of the game files that allows you to get full access without any sacrifice.