There’s simply no “HN is not for self promotion” policy. You’re asked to not use your account primarily for self-promotion, and repeats are allowed, so you can roll your dice multiple times on your Show HN already as long as you’re otherwise a good contributor to the community and only do it sparingly. Flooding another topic with commercial promos simply turns it into another https://news.ycombinator.com/show, what’s the point then?
As for YC companies getting Launch placements, well too bad, it’s their site, you’re free to leave and start your competing one. I assume most users aren’t bothered — I seldom notice them and hardly ever click on them. I notice job ads more.
One thing I do like: When people call themselves out -- "hey, we buy this software... or I work for this company and you might like this software"... then they share some software that is relevant to the discussion. I rarely see those kinds of contributions downvoted due to their transparency. Plus, I learn about lots of interesting companies and solutions that way.
As for YC companies getting Launch placements, well too bad, it’s their site, you’re free to leave and start your competing one. I assume most users aren’t bothered — I seldom notice them and hardly ever click on them. I notice job ads more.