At the same time, if a few people riding the system that way is the price you have to pay to help the people who truly need it, isn't it really worth it?

I feel like random altruism makes us feel good while probably doing very little actual good. As the OP said, it's haves giving to haves.

As a have, I'm cool with this.

I think what the grandfather post meant was that Jonathan's card is meant to be scanned from a cell phone. If things like this are restricted to people with a cell phone (or a facebook account, or an iphone app...), the system selects for beneficiaries who are already above a certain level of need.