He is paying $100 for a bunch of add-ons, which have no idling. He is not paying anything for his dyno. The only current way to avoid this behavior is to pay for a dyno.
If you don't like this behavior, that's something to complain about. I'm just stating facts to help explain why his assumptions are incorrect.
It's interesting. I created a simple app (using the free dyno), use the free new relic monitoring and that keeps the app fresh (no idling). And I have no traffic coming to the site. All i'm paying for is SSL. I would think he would have no idling with multiple services pinging it for uptime.
If you don't like this behavior, that's something to complain about. I'm just stating facts to help explain why his assumptions are incorrect.