It is not an obligation - simple fact. You can't objectively disagree with that statement. The content of games/movies - they are just content. Like you mentioned, if the game is on average very scary, has insane noises, flashing lights, gore, violence, adult themes, etc., the developer should put a warning sign or have it mentioned in the game. Otherwise, it is okay. This game does not have jump scares and it does not matter if the person is horror enthusiasm or if they just stumbled across the game - it is simple as that. There are majority of people, who consider my games being "not scary", yet I watched 1 person, who literally was screaming, while playing one of my games - this does not mean I must put a sign that the game is "SCARY".
Edit: Again, the statement of "developer SHOULD always mention" is factually wrong.
There is nothing wrong with putting a jump scare warning. I'm not even saying that they should or they shouldn't. I'm just saying that some people feel more comfortable knowing what they can expect from the game and that is something that developers can choose to respect or not.
Requesting that games should have a 'jumpscare' warning is absolutely valid criticism. It's up to the developer to decide whether or not they'll act on that criticism and it seems that they have so it doesn't even matter what we think at this point, I'm not sure that it ever did.
I don't know what comment did you read, but they never "requested", rather made a statement of something which is objectively wrong. Furthermore, I never said there was "something" wrong about putting a warning sign. Clearly you either did not read what I wrote or were not able to comprehend what I was saying. And frankly speaking, it does matter even more now, because the developer was "forced" to do something they never intended. That's not good. If someone has a valid argument or criticism it should not be based of one's subjective feelings. It is not a valid criticism and if you deny that, more power to you, yet it won't be correct.
They never demanded anything. The original poster said they 'should' put a warning, not that they 'must' put a warning.
That's not a demand, it's a suggestion and an important one.
Anyway, the developer already added the warning and I'm sure they're not concerned about any of this.
It's not that serious.
Must and should express the necessity. Both "must" and "should" are axillary verbs. The term "should" is used to discuss duties, obligations and if something is right. We can also use it to do anything in a specific situation, specifically if judging someone's activities.
Come on now, you disagree at everything I say with minimal arguments if none. As for the developer, once again, they should not be demanded or treated like that. And clearly based on the down votes, gladly I am not the only one who disagrees.