This means that variance is not just "psychological", there is a real economic cost to variance. These days you might get away with saying that if you're a Vulcan you're better off mining solo, but in the future when mining will be one in a million chance to get $100M even that much won't be true.
That's incorrect. Even at insane difficulties solo mining pays more on the bottom line. The chance to find a block solo decreases as much as the average payout of a pool, the relationship between both stays invariant.
They were just saying that the utility of money does not scale linearly. To a dirt poor person $1,000 guaranteed is better than a 51% chance of $2,000, or a 25% chance of $5,000, or even a .1% chance of $2,000,000, while the math would tell you to just take the odds x the value to get your expected value.
I think that's still a little far fetched at the moment, since a block is only worth about $750 today, hardly life changing money to most.