That's anybody who has enough money that they don't have to work. It doesn't tell you anything about where they got it.
> You're begging the question - why was it your money in the first place?
What if you found it in the street? Would that affect whether or not the business you invest it in produces a net positive as a result?
> But if it's just privilege that you had, then you don't get any credit for allowing it to be used productively.
That doesn't seem right. You could have spent it on drugs and sex. Your choices matter.
> If you do something that produces real value in the world then that's positive sum - if you turn some planks and nails into a table, that table is more valuable than the stuff that went into it, the world is better off.
Suppose the planks are the status quo. You're getting paid $10/hour to make tables. Now you get a raise and get paid $12/hour to make tables, but you still only make exactly the same number of exactly the same tables as you did for $10/hour. The extra $2/hour is zero sum, isn't it? Why should you get it instead of the boss or the customer?