Subscription payments are used with pull-based payment methods (e.g., ACH, credit card, etc.)   At the protocol level Bitcoin is a push-based payment technology.

There are no payment processors yet today that support subscription billing.  Eventually some provider will provide this.  It will probably involve the subscriber having to keep funds in a wallet with the payment processor in which the processor draws from at the subscription renewal time.

Why would he turn down any income in exchange for the fact he may only get paid once? If the person only buys because he accepts bitcoin and may be a dust coin collector and miss a month he still got the 1 payment he wouldn't have gotten. It is so easy to accept and integrate into a site as well.