Simply said, because in this day and age everyone has been told that they are special and unique. By their teachers from kindergarten on, by society, and by their peers who are too afraid of scathing reviews on social media to say otherwise.
The concept that one does not always get their way is foreign as a concept, as is the idea that one must work for certain things. Because these people were assured of their mental superiority while they grew up, namely that they were the best at what they did (even if they were not); in the real world they are prone to violence and mob mentality; when faced with divergent opinions as they have no concept of how to debate, or reason with another in a non-violent manner.
That doesn’t work in the digital world, and so they demand Game Developers / Directors to fall in line by make threats of quitting their game, or boycotting a movie. They erroneously believe because of the delusions they have claimed as reality that the loss of their presence will be a nigh-on-biblically tremendous and earth shattering event that spells the end of the franchise. Such is the height of their arrogance.
You can see this in PVP with the people that say “Follow my strategy and we will win!” as if they were Napoleon reincarnated (who didn’t have the best record, but history isn’t taught either so…) At the conclusion where they lose, the same people fire off a “You stupid {insert X expletive}.” or something equally disgusting.
In PVE and so they believe they should be given buffs while the classes that beat them should be nerfed, and since their vision is superior to the Developers who created the game they should be heeded IMMEDIATELY! Or else they will quit, though in their most private moments they know they lack the capacity or wherewithal to do so.
If people want to blame anyone, then a person should all blame them self first and foremost, and then change. That is my advice. Be a team player, be willing to lose, and sometimes accept that you failed magnificently. Then beat your insecurities and become a better person for it.
Maybe also take a page from the Void Elves and “Question everything.” If you blindly accept a narrative without facts, or corroborating evidence; then you failed at the grand game of evolution, and you have regressed rather than evolved.