The problem with investment dollars is that they're typically "spent" (invested) only when they can extract more wealth than they create. You invest $10,000 now so you can have $15,000 later. Where did that $5,000 come from? Well, someone gave it to you in exchange for that $10,000.
In other words, they're effectively rent-seeking dollars. The whole hope of investment is that you get more money without doing any labor yourself.
And if you invest and they're lost? Well, now it's not even rent-seeking. It's just burning money.
This isn't to say that there's no benefit from that money being available. The issue is that the real value that investment creates isn't really the money going back to the investor. It's the value of the labor and products generated by whatever the money fronted costs for. The actual value is still generated by the labor. The investor does help start the ball rolling, but is still a leech.
Once we get to shareholders, things don't really improve. Shareholders are also only interested in dividends. They want dividends at the cost of the company. At the cost of the product. At the cost of the customer. There's no responsibility to society or to the customer in the face of a shareholder.
Shareholders are like employees that don't do any work but still want a paycheck. "Oh, but they're owners," is kind of a poor excuse when these owners do no work. Stock is like buying a box of Crackerjack and letting your brother take the whistle and sticker.
> Also, as for JK Rowling specifically, she had donated a significant amount of her wealth to charity.
Which she does because donations offset the taxes she owes. She's no Dolly Parton.