Sure, we can argue about whether it is measuring that correctly, but my point is trying to look at how well billionaires have done at creating wealth for others.

All these commenters listing people for inclusion who created a great deal of wealth but aren't/weren't billionaires (many of them not even wealthy) are missing the point of the list.

No, that's not my point, as a commented elsewhere. Even restricting it to "outside investor returns generated by billionaires", this list is only looking at outside investor returns since the IPO and in excess of T-bill returns.

Drew Houston generated tons of wealth for outside investors, but only for pre-IPO investors, hence he's on the list with a -3B number, because post-IPO investors have done so poorly.