Since I'm in a 2 hour car ride I might as well throw in my opinion.
Teaming has always been a part of this game, since the beginning. When you've been playing for 2+ years like a select few of us have, teaming is the only way to keep you semi-entertained by this game. What makes teaming fun (for me at least) is the fact that you can your friends can play and have a good time without a large risk of you guys dying, which leads to the ability to doing something fun at the end of the game. There's a difference between doing that against solo players and against teams. With teaming servers and FFA servers, if you decide to team, virtually everyone else in the game will be in a team along with yourself. Aside from that, when I do decide to play solo, fighting teams is what gives you a slight challenge. I, myself, win nearly every game that I'll be in without a team in it. (Which isn't very many considering I like to scrim and battle). Anyways, without teams the challenge aspect of the game goes away. As people said before, teaming will also take away the "Hunger Games" aspect that Survival Games had had all these years. If you take a look at the vote, about 33% of people say no to this, which for the most part are the experienced players who know what doing this would do to the servers.
I typed this on mobile, I know there's multiple topics in one paragraph ;-;