Dialogue you mean, conversation-debate, not dialog the screen displayed element, for interfacing with the user.

The group screaming the louder is considered to be correct, it is pretty bad.

There needs to an identity system, in which people are filtered out when the conversation devolves into ad-hominem attacks, and only debaters with the right balance of knowledge and no hidden agenda's join the conversation.

Reddit for example is a good implementation of something like this, but the arbiter cannot have that much power over their words, or their identities, getting them banned for example.

> Even here it's the same, it's comments with replies but it's not truly a discussion.

For technology/science/computer subjects HN is very good, but for other subjects not so good, as it is the case with every other forum.

But a solution will be found eventually. I think what is missing is an identity system to hop around different ways of debating and not be tied to a specific website or service. Solving this problem is not easy, so there has to be a lot of experimentation before an adequate solution is established.