Plz explain why this was able to be surrendered....

So heres the thing. This game, was heavily in our favor, literally no way the enemy team can win, our ahri DC's for a second, like she was pretty much the entire game, im wrecking face cause im fed as khazix, Ez is really fed, and yet, my team surrenders for no apparent reason... up 10k gold, and 4 towers, and 2 dragons... Why do i lose 22 LP due to trolls? Is there any way we can fix this? Like maybe not be able to surrender if you are under 5k gold behind. Riot talks about getting rid of toxic behavior, well this is the root of the problem, as well as feeders and afks, so why not attack the root of the problem instead of the leaves?