[imtringued]

Sometimes people just want to talk about a certain topic, regardless of the article's contents. The headline just gives them a convenient excuse.

[TeMPOraL]

As 'CPLX says, for many of us the article itself is just a discussion prompt. Quite often (I'd say half of the time), the tangents and off-topics in the HN discussions are way more insightful and interesting than the submitted article.

[OJFord]

Almost all of the time I submit something, that's exactly why: I want to read the HN comments, but there aren't any yet!