IMO this ends up being way more advertorial (for Bauer) and lacks all of the engineering context (urethane inserts! damping! "the dichotomy between nature and human technologies"!). But, understood.
Perhaps; I haven't read that closely. Obviously it's great if you're writing something better about a topic, but there needs to be a specific URL to what you've specifically written about it.
I read your newsletter. I didn't read as much of the other article.
Is it really unclear what the issue here is? The issue is that the OP was too promotional. Indeed your account history on HN has been, basically, entirely promotional. That's not really what the site is for. This is in the guidelines: https://news.ycombinator.com/newsguidelines.html.
On HN, the idea is for people to submit stories that they ran across and personally found intellectually interesting, not because they have something to promote. It's fine to post your own work occasionally, as long as it's interspersed with interesting posts from other sources. But if you only submit promotionally, it feels like you're not participating as a community member.
To be fair, the stuff you've submitted has been good, certainly not spam. But the newsletter thing was a step too far.