I don't know what raid groups YOU'VE been in, but it's been quite common for at LEAST the five years -I've- been playing for anyone to roll on loot whether they died or not. Which means yes, if they stood in the pool on Putricide, or ran into the pipe slime of Festergut, or forgot to change sides on Hydrox, or ran late when they were the bomb on Solarian, or caused the death of a healer by forgetting to grab the Big Spike on Naj'entus, or moved in the Flame Wreath on Aran and died, they still got a chance to roll for loot. Oddly enough, we still called it raiding.
Those people who died to stupid were either called out for being stupid, had DKP docked, subbed out, etc.
LFR is a fun way to kill time and grab some quick loot, but it in no way teaches people how to raid. It is just a glorified heroic dungeon.