While it'd be nice to ban sites that exhibit negative behavior, Oath sites represent some of the largest news properties in the world. Yahoo News is the #1 news site in the US, HuffPo is also in the top 10. Together, they have more traffic than the next 3 or 4 largest providers combined.
Further, several of their properties are specifically relevant to the HN community, including TechCrunch and Engadget. Not saying these are the highest quality sites out there, but they are the original source of reporting for many things discussed on HN. In fact, I see 3 different TC articles in the first 2 pages just right now.