Why is the community like this?

A little context. Playing Ryze top lane. Doing okay, got first tower, big CS lead on a wukong. Turns into a pretty close game. Our jinx ignores a baron call and goes to solo drag. The 4 of us at baron end up dying, enemy team gets baron and eventually wins the game due to that singular play by Jinx. I give her the slight roast. Not the full flame, like a cheeseburger, just a slight lil roast. I mean, she single handedly lost us the game by not coming to baron. However, my team mates vowed to report me for negativity rather than Jinx for losing us the game. Why does the community view negativity as such a bad thing when it is in response to people throwing games?