Indeed, a virus was responsible. But I do think the accumulation of extreme wealth played a role in the following way: Wealth influences policy. So far, virtually all policy discussions have focused on a tradeoff between saving lives, and saving "the economy" implicitly while leaving private wealth untouched. A focus on protecting stock prices -- a measure of wealth -- definitely played a role.

A little more speculative is my suspicion that a capitalist society storing its surplus in private hands may be correlated with a society that is unprepared for a crisis of this magnitude. The first time the President came on the radio to talk about the crisis, his tacit message was: We are hopelessly unprepared for this.