>>That is not what the term "risk" means. "Risk" also includes all the investments which did not pay off.

That's certainly true, but I'm not sure what you're getting at. I'd appreciate it if you could clarify.

Diversifying your investments to hedge against those that don't pay off is the foundation of modern portfolio theory. You can see it in action at virtually every level of society: individual firms have employees that don't generate returns, but they hope that the collective productivity of the entire company can generate a positive return, angel investors and VCs invest across a broad spectrum of companies hoping that a few big wins will offset those investments that don't pay off, and governments invest in a variety of projects, research, and (sometimes) companies that they hope will generate positive returns for the economy as a whole.