If the streamer says "don't help" then it's the fault of the people trying to help if the streamer gets upset. Though in my opinion something like "lots of dodging on the last boss" isn't exactly game breaking, so the streamer probably overreacted a bit. However, coming to the forums to vent their frustrations about that streamer probably wasn't the best idea. Both parties are guilty of overreacting to something trivial imo.