Apparently, the purpose is to be an ass...

The fact that this obscenely wealthy person defending the obscenely wealthy is so very wrong pretty early on is reason enough to discount any argument he subsequently makes: 

Google’s contribution is obvious. What about investment banks, with their complicated financial derivatives and overleveraged balance sheets? Conard argues that they make the economy more efficient, too. The financial crisis, he writes, was not the result of corrupt bankers selling dodgy financial products. It was a simple, old-fashioned run on the banks, which, he says, were just doing their job. 

Really.  He argued that, thus demonstrating a complete lack of understanding of his own fucking industry.  Could any rational person believe that this guy is capable of positive contributions to society? In multiplier talk, I would argue that his wealth likely has less than a 1x multiplier, meaning he would produce more economic benefit if all his money were redistributed to people with a clue...or at least people who need to buy milk. I don't doubt that there are wealthy investors who have wealth multipliers >1, and in some cases maybe >>1, but this idiot isn't one of them. 

That said, let's assume that his multiplier is > 1.  If such a terribly stupid person, just by virtue of having wealth, had a multiplier or > 1, then there is nothing inherent to the wealthy that justifies any individual having such wealth other than the wealth itself.  It's a circular argument.  And it follows that if the only economic benefit that wealthy provide is simply having wealth, then there is a strong social good that could be done by having wealthy people not be assholes, and probably not be idiots as well.