The OpenStreetMap.org website doesn't ban commerical sites (per se). The volunteer sysadmins who manage the donated hardware that runs the OpenStreetMap.org website don't offer any SLA and reserve the right to ban people/apps which put too much load on it. If you don't like it, they're prepared to give you a full refund.
"Which maps should we investigate deeper?
Some options we could reject quickly for various reasons. OpenStreetMap is not supposed to be directly used by commercial sites. Apple Maps, even though we wouldn't mind having Apple logo on our site somewhere, was just released as beta and requires Apple developer account to test properly."