Well, of course there are other subtleties involved, but even the money that I pay for a given stock doesn't just go to the company unless it's an IPO. It might indirectly benefit the company because I'm adding to the demand and driving the stock price up, which helps all holders of the stock, including the company that issued the stock originally.

However, my point is that people are not buying stocks to own OR to benefit the company. They're buying stock so that a "bigger sucker" will come around later and buy it from them and they can make a profit.

So I guess it depends on who we're talking about when we say "primary purpose", but for anyone who is purchasing stocks, the primary purpose is NOT to be an owner of a company. The primary purpose is to speculate.