HN is for sure used to gain a specific audience. It takes about 10-20 managed accounts to get a thing on the frontpage if you distribute the votes right. This is why I in 2016 made the "no noise hacker news" chrome plugin. I could link directly but I think its bad practice - so search on your preferred search engine. From the description:

    This extension will filter stories from domains that - per november 2015 - had more than than 2500 submitted stories but less than 40% had more than 3 votes. Domains with usergenerated content (as github.com or youtube.com) are not included.
    
    Is this censoring? 
    - No, this is a way of limiting domains with a high amount of noise.