You are wrong. MCSG isn't dead, it just isn't as popular as it once was. The game mode is classic, it will always be fun. What died is the community, I'm not going to speculate why other than saying the community killed itself from the top down.
First off, don't take this reply personally, as I don't know you at all and just want to have a decent debate.
Problem 1: Repetitiveness
This game is getting old to people who are 1) winning pretty much every match or 2) losing every match. That skill gap is widening.
I can only enjoy MCSG in teams now because it gives you something to talk about while you connect with others, but on its own it is pretty repetitive. I don't know how you feel but I can only enjoy looting chests for half a game and killing people for the other half fun before I get tired of it.
Problem 2: Lack of Change
You might be just fine with the gamemode but you can't deny that even Minecraft itself will no longer be popular one day. (I'll use the whole of MC for an example here.) Sure, it's flourishing now, but that's because of updates and changes that give people something to talk about, along with people figuring out how to use said updates to make newer, better, and awesomer things. Therefore the community is growing and changing.
MCSG? Updates hardly ever touch SG's main mechanics (which encompasses practically the whole of the server) and because of that we get bored.
Boredom causes trolling which causes flame until people stop caring, then people get bored again, and MCSG's community has been stuck in that loop for ages now.
Problem 3: Lost Faith
Am I saying it's the staff's fault? Not most of them, and I'm glad we're at a time where people don't point so many fingers at the devs. But I know that
at least I am losing faith that things are actually going to change for the better.
Thanks for reading. I got pretty carried away there, but I haven't had something to fight for in a while