It's possible to contribute to HN without being a member.

For instance, you can talk about it around you, share links with people outside of HN, either via mail, twitter etc.

I've been doing this for months before being more active, submission/commenting-wise.

You don't need to contribute to HN in order to appreciate what makes it special - the focus of submissions and quality of comments. Petewailes seems to understand this, so I see no reason to raise some silly "rule" (a general guideline, really) as an excuse to ignore the point he's trying to make. If you disagree with something he said, how about you say so and explain why. Pretend I said it, if that'll help.