If you broadcast to all relays, relays will need to moderate it - either block it or remove unwanted content . They may choose to block/remove only notes containing unwanted goods/services, or, more likely IMHO, just block these event types for simplicity. Otherwise, they'll risk prosecution.

I don't see a compelling reason for operators to host notes advertising, say drugs, guns, hitman's services, and risk being prosecuted, while at the same time getting no benefit from hosting them.