He obviously doesn't in a legal sense, but in general it's good manners to follow the guidelines (if any) set out in the opening post. Also known as staying on topic.
What I really dislike, and what happens way too often on this forum, is when responders stay on topic, but the OP doesn't like what people are saying, or doesn't want to discuss it anymore, and can then say "topic closed! no one can respond anymore!". That's just rude. If the OP doesn't want to participate anymore: fine, he can unsubscribe. Killing the discussion for everyone else serves no use, besides being a parting shot of "I can't come up with any response to your 2 hour essay... so now no one gets to respond so you wasted your time. HAHA!"