Is Hacker News deeply rooted in Silicon Valley, and isn't it well known that Silicon Valley do not share conservative views? I think the answer can be derived herein.
This is a common misperception, but no, the overwhelming majority of the HN community is located nowhere near Silicon Valley, and the flags are coming from HN users, not admins. So what you're seeing is (a) community behavior and (b) not particularly SV-related.
>and isn't it well known that Silicon Valley do not share conservative views
If Silicon Valley didn't share conservative views, there wouldn't be so many articles and comments defending said memos, and the views expressed therein. Certainly, what's "well known" about HN and SV seems to depend on what set of cultural or political strawmen one wants to punch down. I've seen both described as wretched hives of leftist cultural marxism and alt-right fascism.
>I think the answer can be derived herein.
Yes, but not for the reasons your comment implies. People who are strongly ideologically driven are more likely to engage with these threads - they're likely being flagged by people who are tired of seeing the deluge of content which they feel is off topic, or no longer delivering anything of insight or quality.