That's just good ol boy bullshit. After I read about that, it became dead to me.
HN has super voters. There's also a trait that your account can be tagged with which makes content that you share less likely to get to the front page (all votes on your content count as some percentage of a "real" vote). That attribute is usually added to non-insiders whose content often makes it to the front page.
I don't think they do it out of malice. They are design decisions in service of amplifying/dampening some desirable/undesirable effect. It doesn't make the creators evil, it just means that they have goals, metrics or influences other than the purity of their voting mechanisms. Community sites are super fucking hard and the people who have built successful ones have my respect.
I've noticed for a while now that I'll only receive a fraction of total points for a submission, perhaps 50-60% of the submission's displayed upvotes.
I think this might be human nature. My wife told me about the group behavior of a Facebook group she belongs to (women's fitness Facebook group), and how over time some of the women become mini-celebrities – everytime they post anything, they get all the Likes and comments. Human networks just seem to naturally coalesce this way, with power law distributions.
I'd go so far as to say that all niche markets have non-disclosed "syndicates" of sorts. Life and wealth seminars, professional conferences, information products people, church leaders, podcasts - all promote other people/products/things similar to themselves who also promote them.
It seem more important to understand this and to take it into consideration when looking at something like AngelList or PH. Advocating that these organizations work against the grain of how all niche markets work seems unlikely to be effective.