I have no issue with the people that invented a specific technology getting rewarded for that. But that's not what's happening here. You're giving a few early adopters most of what you want to then use to price all the assets in the world.
I'm not sure anybody is saying that bitcoin will be used to price all assets in the world. USD currently isn't, for example. It's just the dominant currency.
A reasonable estimate for all the dollars in the world is 10 trillion. Say that bitcoin being a full sucess is it being valued at a total of 5 billion. Now consider that Satoshi has about 5% of all bitcoins that will ever exist. That puts him as 3x richer than the current richest man in the world. I don't see anything in bitcoin that justifies that kind of payout and that's for the inventor of the thing.
We don't have a justice system. We have a legal system. And this seems to be allowed under our legal system, so I'm not sure the moral argument is valid.
Why do you feel it's immoral for Satoshi to own 5%? We don't even know if he's alive or still has access to the coins, but let's say for the sake of argument that he does.