HN is “for” startups. This is a startup. What’s the problem?

The problem is neither with HN, the statement was not about HN being or not being about startups (though I would not say personally it is "for startups"), neither it was against startups or other starting groups showing projects. The problem cited is about lack of clarity and supposed change of topic, not the chosen audience.

Now, what is your comment precisely about, cause I'm pretty sure what mine was?