Not sure exactly what you're asking, but the post was flagged by users and penalized by moderators, probably for the same reason: the story had already had a major thread on HN. Also, petitions have traditionally been treated as off topic here.
It is too bad HN will not support an ongoing discussion among interested HN readers about an ongoing issue over arguably one of YC's most successful projects. I understand splattering the front page with > 1 link is too much.
However, one persistent headline among 20 would not bother most people (aside from the powers that be who may want to quell unrest, of course). I missed earlier discussions and only came in during this one. I think the debate over how to create a successful social network, and how and where to limit free speech online while managing a large community, ought to be of interest to anyone with skin in the game. And that thread had plenty of upvotes and comments to survive beyond two hours.
This story has had major threads on HN, including on the front page right now [1]. Our interest is not in quellage but in keeping the front page substantive, i.e. keeping HN HN.
Big drama always brings many copycat posts and follow-ups. Most need to be treated as duplicates or drama will fill the front page, which is not what HN is for. Where to draw the line? Our answer is, have a major thread on (hopefully) the most substantive version of a story, plus a new thread when there is significant new information [2]. That's the best way we know of to balance the different factors, though we're open to a better way if anyone suggests it.
It's true that it's common for a user to miss earlier discussions, as you mention, but that's a problem with HN in general. No one sees all the threads. We try to point to previous discussions when we notice them, and many HN users helpfully do so as well (greenyoda and ColinWright practically deserve medals for it).