I have thought that through and considered putting that in my post, but I didn't want to dilute the original thought.
Of course I support the idea of "off topic", but it is something that needs a lot of consideration and however one writes such a restriction, it's liable for abuse and probably has a zillion edge cases. E.g. is it off topic if I post "<your favorite politician> hates cat videos" onto a cat video forum? What if I am a moderator with <other side> political views, and I allow those posts if they come from people that agree with me and disallow them if they come from people who agree with you? What if I divide my site into multiple sub-fora, one of which is "politics of cat videos"? What if de facto use of my forum or a sub-forum becomes political discussion, but that everyone attaches a cat video to each post?
In other words, yes, I have thought a lot about it, but this warrants its own separate discussion.
That's a very reasonable response. I'd add another thought: A site (e.g., Twitter) could define "off-topic" as anything that goes against its Terms of Service or Code of Conduct (CoC), which would probably result in exactly where we are now. Same problem with a lot of similar ideas - "Spam? Anything that violates our CoC is spam"; "Degrades the experience for the user? We feel that violating our CoC degrades the user experience"; and so on. Not a problem easily (or even able to be, IMO) solved.
Of course I support the idea of "off topic", but it is something that needs a lot of consideration and however one writes such a restriction, it's liable for abuse and probably has a zillion edge cases. E.g. is it off topic if I post "<your favorite politician> hates cat videos" onto a cat video forum? What if I am a moderator with <other side> political views, and I allow those posts if they come from people that agree with me and disallow them if they come from people who agree with you? What if I divide my site into multiple sub-fora, one of which is "politics of cat videos"? What if de facto use of my forum or a sub-forum becomes political discussion, but that everyone attaches a cat video to each post?
In other words, yes, I have thought a lot about it, but this warrants its own separate discussion.