Because there's a level of anonymity on the internet, especially on a gaming forum where the audience tends to skew younger and not everyone knows how to deliver feedback in a mature and comprehensible way. It's been like this since the old H3/Reach BWUs. People would get mad over BR/DMR bullet spread, playlist updates, reticle bloom, armor lock, whatever was important to them. If you decide to reply to any of them it's best to not get too carried away, or better yet just ignore it altogether.