Also, a lot of those media and BigCo stories really are of interest to the community. We try to dampen the stuff that's repetitive, and most of those sites are downweighted by default, but HN would not get better if they were excluded. It's all just more complicated than it seems like it might be.
What ultimately matters is how interesting a story is, not what site it comes from. I'm suspicious of encoding proxies for that, because it would be easy to end up optimizing for the wrong things. https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...