OK, but how many physicists support the moon landing conspiracy? How many aerospace engineers support the moon landing conspiracy? What credentials do the experts of the moon landing conspiracy have that I should trust?

I think he has a valid point if you have bias in which experts you place trust. There are, in fact, a lot of experts -- and even academically tenured, credentialed, published experts -- that I agree, don't have much of anything worthwhile to say.

Ya, true. There are particular areas though where 'wisdom of the crowds' works much better than any expert, and then there are obviously areas where it does not.

I'm not sure exactly what the properties of each type of problem are, but it doesn't seem at all obvious to me that stock picking is not one in which a sort of herd optimization approach might be very effective.