I think the difference is mediums that have reached a certain size and cultural influence that they are effectively modern public forums. If all public discussion is on happening on these private platforms then they a civic duty to not suppress speech.
What's happening is people conflate "not suppressing speech" with "supporting hate speech." They don't support anything. They're nothing more at this point than a public space maintained by a private entity. Private entities I'll add that are essentially subsidized by taxpayers due to not meeting their obligations of paying their taxes, and no I'm not talking about minimizing tax obligations[0].
Obscenity as a legal term is complicated. Culturally, even more so. One person's "obscenity" is another person's "vernacular of the street." What is obscene in Kuwait might be an everyday greeting in Sydney.
Primarily, you are arguing for compelling corporation to expend effort and expense to carry content deemed objectionable by officers of that company, and I'm not sure you've thought that through. You might think politically-[whatever] voices are being silenced--absent evidence--but if the US government decides to violate hundreds of years of established norms and force websites to cease censoring content, it won't be just content you favor that explodes. And if the US government can force Facebook and Twitter to carry content they don't like, then what legal standard separates them from Hacker News, for example?
I'd rather leave the definition of obscenity to the courts than to a private company.
If a company wants to editorialize their content and provide moderation when they deem fit then they specifically should lose their protections under section 230.
That is completely the opposite of how section 230 works, and section 230 is the entire reason websites like Hacker News are allowed to exist. Your argument has now gotten even worse, not better!
If a company loses Section 230 protections, the safest move is to disable user content completely. No comments anywhere. The next-safest move is to be extremely heavy-handed editorially, since any comment left alone could be the basis for a company-ending lawsuit. Whatever views you believe are being censored now, I guarantee you they would be actually censored completely without Section 230.
Read Section 230[0]. It's the foundation of the modern internet and says almost exactly the opposite of what you're suggesting. Read 230(c)(2)(A) twice.
What's happening is people conflate "not suppressing speech" with "supporting hate speech." They don't support anything. They're nothing more at this point than a public space maintained by a private entity. Private entities I'll add that are essentially subsidized by taxpayers due to not meeting their obligations of paying their taxes, and no I'm not talking about minimizing tax obligations[0].
[0] - https://www.theverge.com/2020/2/19/21144291/facebook-irs-law...
And nobody ever said "no matter how objectionable." We still have limits on obscenity.