I think you're right, but I guess some people thought your comment didn't add to the discussion.

It did answer the original question. I wouldn't have downvoted it, but I wouldn't have upvoted it either.

That said, I do believe it's not the best suggestion (especially since pud seems engaged and interested in growing the site).

You are right. You were not off-topic and the fact it is poor advice is only a judgement, not the absolute truth.

Maybe I have misused downvoting here. Can't downvoting be used to express disagreement instead of just reporting a misbehaviour?

I believe downvoting is only available to users with high karma. This makes me believe that downvoting is meant to fight misbehavior. Unfortunately there is no way to report misbehavior of downvoting. If you already have high karma you have a conflict of interest in reporting downvoting misbehavior.

Actually, it seems that downvoting for disagreement is a ok behaviour:

pg: http://news.ycombinator.com/item?id=117171

I will stop using downvotes for disagreement then.

(Actually I think it is the first time I use this downvote feature on HN so the damage is fairly limited so far).