Hummm...don't be so quick making such a blanket statment.

1. How do you insure your portofilo doesn't go down in value?

2. How do you generate income from your long-term holding?

3. How do you diverisify your large holding of single stock without selling your stock and to avoide tax?

4. How do you insure your bond holding doesn't defalut?

5. How do you benefit from interest rate movement that is aganist your?

...................the questions go on and on.

and many other suitable place for options, future and other deriviatives!!