I don't believe deferred altruism is as good as it's cracked up to be, because of the importance of motivation. If you tell someone who wants to work in a homeless shelter, "Go to Walk Street instead and give away your wealth" you may be correct in theory, but in practice that person might be a terrible banker and burn out quickly. To desire money instinctively, the way most people crave hugs and candy, is actually rather rare, and most of the rich people I know desire money that way, while most of the poor people don't. I'm not sure an altruist can make himself obsessed with money in order to be a better altruist. I've seen people try and fail.