I respect your POV. Everything has risks, even your commentary: One person might read it and think that you are a sober, responsible individual, while another (especially on a startup forum) might read your words and worry that you are too risk adverse.
So I agree there is a potential cost, and if it's too high for you, I respect your position even if I don't follow your strategy.
The other bits of strategy you espouse would not work for me personally. If I write privately, I don't get any feedback. For example, let's start with the assumption that this essay is terrible advice. How would I know that if you didn't read it and tell me so? How would I know that the extra length looks like malicious SEO optimization if some nice person elsewhere didn't accuse me of trying to manipulate Google?
Only by publishing my writing do I get the feedback I need to improve. And I get it immediately, no delay, and with no sugar-coating or tactfulness that might come from circulating my writing to a trusted group of friends.
Also, you say only release the gems. How would I know what is a gem and what is not? I don't want to bore you with more examples, but many of the essays people have thanked me for writing were ones I didn't think would go anywhere. Were I only releasing the ones I thought were gems, I'd never have written them.
Now as to harming the reader. I take the position that HN takes care of that. If I write something and it dies on the new page, only a few people wasted their time. I'm not suggesting that there be no filter on my writing, I'm suggesting that aggregators like HN are the filter.
Compare and contrast this to the situation a few years back, when people used RSS feeds. In that case, all of my subscribers would probably read everything I write. Yes, after a while they would drop my feed if I was wasting their time. But today... I don't even offer an RSS feed or a consistent source of my writing.
If people like it, it gets around. If not, it doesn't waste that much time because it doesn't get the upvotes or the retweets to do much damage.
I can answer the question of whether my writing is marvellous. It isn't. At best, it follows Sturgeon's Revelation: 90% of it is crap. My argument is that publishing 90% crap is working for me, although I can appreciate the argument that either it isn't really working for me or that it isn't a good idea for someone else to blindly copy my strategy.