I could not care less to see Miiverse go. It started out really fun, and I actually enjoyed it for the first year of the Wii U's lifespan... then things went downhill...
It started with the Thanksgiving update in 2013. Nintendo decided that the Miiverse community needed to be more thankful and less selfish so they removed the "yeah" counter (the Miiverse equivalent of likes) from everyone's profile. The update removed a feature... and that was it... it was also something people really enjoyed having just so they could have some numerical sense of how fast they were growing as a personality. Thats basically first nature to social networks, so it was just an odd choice. It wasnt even just for Thanksgiving either, they never brought it back after that.
Then there was the next big update. This time they limited each user to only 1 post every 5 minutes. Not just post as in a message on the public community, but any form of message was limited to 1 every 5 minutes. If you were messaging a friend you could only send 1 message every 5 minutes. In a comment discussion, you could only contribute 1 comment every 5 minutes. This limit was eventually lowered to 3 minutes due to the overwhelming backlash but still, they intentionally made a "social" network less social...
Then throughout the course of Miiverse's life we had thousands of users complaining about "false reporting". People would make seemingly innocent posts that would later be taken down for containing "spam" or "spoilers" which they did not. Many innocent users ended up getting banned because of this. I personally got banned twice. But just in case you thought I was just being overly dramatic about this-- the moderation got so bad that even one of the admins got banned from using Miiverse. I can only guess that the bots read her official gaming news and saw it as spoilers.
Then there was the last major update that completely overhauled Miiverse. The big change was that they removed posting directly to a community. Instead you you were limited to posting screenshots, asking questions (which had to follow their specific guidelines), and posting to your play journal, which was limited to 30 posts per day and nobody ever read.
So in the end it was left as a big pile of shit. They refused to fix the things that were clearly wrong with it and only seemed to make it exponentially worse over time. So now lets see the petition and see just what they want to keep Miiverse around for.
"Miiverse has been the most amazing social revelation on a modern console system."
It was certainly interesting but I just pointed out every major reason why it was terrible.
"The community of artists and gamers gathered there have helped create a unique and special place."
Gamers can talk about gaming anywhere. Im literally doing it right now, on a much larger and more well maintained network. As for artists, Miiverse did not invent pixel art, and they can live on through online blogs.
"Now with The Nintendo Switch promising a new subscription based mobile service it seems the future of Miiverse may be threatened."
Noy "may", its just dead. They have confirmed they are not supporting it anymore.
"We want Nintendo to keep Miiverse because we love the platform and the art and gaming environment it offers."
There are so many better alternatives though, and all of them offer content from all games, and not just Nintendo. And they clearly missed the part about how they are working on a better online community.