Accusing others of astroturfing and shilling breaks the site guidelines. You don't know why other users downvoted a comment, and jumping to public accusations about that degrades this site badly.
If you'd please review https://news.ycombinator.com/newsguidelines.html and stick to the rules when posting here, we'd be grateful. You've been breaking them a lot and we've had to warn you many times already.
We don't micromanage HN according to YC's particular investments in startups; what's in YC's business interests is to make HN as good as we can, because that's what keeps the community coming here. But if it helps, I don't think YC has any investment in Brave.
I hope you just do your job and prevent those systematic organized promotional posts by such companies on HN to get free advertising. The entire accusation in OP turned out to be invalid in the end as shown in many top voted comments. YOU know that this company with its fishy history (taking money on behalf of publishers without their knowledge or approval) and business model has been systematically exploiting HN and you're doing nothing but warning me. Banning me won't solve the problem anyway.
Most companies that produce articles in the hope of interesting HN are trying to "get free advertising" in the sense of attracting readers' attention. If the content is genuinely interesting to the audience here, there's nothing wrong with that.
If, on the other hand, they're using voting rings, astroturfing, or other forms of abuse to spike their ranking because the content isn't interesting enough on its own, that's bad, and yes we spend a lot of time counteracting that. But if you think that's happening, you should send links to hn@ycombinator.com so we can investigate, not post dyspeptic complaints about it in the threads. Those just add noise.