That said, I actually think his theory is a reasonable one and I'm more confused by comments on HN like this one. It sounds like you're saying essentially (1) your buddies disagree and they know better, and (2) buybacks may help the economy overall because they move cash from less efficient businesses into more efficient ones.
Are you saying that the company buying its own shares is doing so because it's not very efficient? Shouldn't efficiency be reflected in the price of a business due to market forces? If the only place a company can find to put extra cash is buying out its own shares then that doesn't sound like a valuable business to me, and in a healthy market I would expect the price to go down, not up.