I was just gonna ask. XD Being like "Hey Soraka, Baron is really a team fight, and we need you alive and not respawning to help the team. We can all fight it when we level okay?" is different than something like ... "omfg! stop feeding! wtf is wrong with you! report after game! Literal trash team! Dumpster fire feeder gtfo" exaggeration are very different things.
Often times, I have found that when players are not playing well or seem to be intentionally feeding, I respond to them politely and make sure they don't have confusion about what they should be doing and that tends to get a great reaction and also pulls the team together. The behavior stops, usually, they were just confused but sometimes they are truly trolling in which case you let it go and can report after the game ends. The problem is that freaking out on people who are trolling isn't gonna help because that's what they want. Come to the boards and do a rant instead XD