I'm simply observing that we have a legal and economic system in which the people who create value turn over a substantial part of that value to people who own things.
Sure. But I'm pointing out that your observation is overly 'simple'. Owning things isn't the passive activity you're suggesting it is. It's a vital function of an economy and people who take on the responsibility have a reasonable expectation to earn money for doing so.
Suppose someone gets rich from cornering the market in silver. What law prevents him from enriching himself at the expense of others?
Suppose someone finds a way to make a mint by selling crappy securities to gullible investors. Is there a law that prevents him from doing that?
Or suppose someone establishes a de facto monopoly in an operating system. Isn't it the law that makes that possible?
If you want to get into a discussion of all the ways the current market is fucked up, i'll be happy to join you. I, for one, think the entire body of corporate law needs to be reconsidered. What I'm addressing here is the common myth that investment profit is 'money-for-nothing', or that business owners earn money by 'exploiting' workers, etc...
If I decide to sell Coke and buy IBM, what difference does that make to anybody but me?
In aggregate, it makes a very real difference. It means Coke won't have as much capital to do its thing, and IBM will have more. If lots of people make this same call (or if you're making a very large trade) it can significantly alter the production of both Coke and IBM in the coming months. This is what I keep referring to as resource allocation. It's a crucial - and often overlooked - function in any large economy. Even in a non-capitalist economy, these decisions must be made someone. And how well they are made determines whether consumers get the things they need, or whether stores are overstocked with a bunch of junk no one wants.