I can pursue an agenda while being both polite and thoughtful. If I were to ask a series of questions, using the Socratic Method, you would absolutely want to

I can pursue an agenda while being both polite and thoughtful. If I were to ask a series of questions, using the Socratic Method, you would absolutely want to know what my motive was before misspeaking and harming your position. Commenters on HN post both to persuade other commenters and to expose their own opinions to scrutiny by the community. I attempt to persuade and be persuaded by other HN commenters. It is useful to add disclaimers so other commenters can see if I have an agenda. Often I do, and it's useful to disclose that so suspicion is suspended and discourse can continue.