So since you grossly misrepresented my argument I'll start off by trimming pieces of your argument that hold no value.
Ad hominen - Who I am doesn't matter at all. All this does is make you look stuck up.
Also I don't recall stating anywhere in my argument that people aren't free to enjoy things how they want to.
This states that "There is a such thing as 'too easy' even for most casual players". I also stated that most casual players do not even realize it. At what point does the horse become aware the carrot is attached to a string? Is it upon putting forth more effort than it deems the carrot is worth or upon indulging in it's taste? The answer is both for even a casual can dislike content for being too simple and even a casual is capable of being unaware that it is the carrot itself they are bored of.
Or perhaps you'd like to point out that I said "They don't have any concept of gleaning enjoyment from challenge.". Is this the part you took offense to? Being incapable of enjoying challenge does not beget negative connotation. With that said I could have worded it better. What was meant is that one who does not enjoy a challenge, does not seek it and therefore when it is met, calls for it to be removed.
It is not stated whether I agree or disagree with this viewpoint.
Next...
Strawman - Where do I state "but but challenges and hard stuff is fun!" or anything close to it? The answer is I don't and you're creating an argument to fight that doesn't exist.
You may be surprised by this, but I actually don't think increasing general difficulty is the key to success and I don't actually enjoy the typical 'make it harder' content. Bullet sponge enemies are the least creative, least enjoyable method for increasing difficulty, but also the most popular. What I do enjoy is unique mechanics, a good story, great atmosphere and paths to individual achievement.
My statements were that games constantly become easier and more streamlined to a detrimental point. I provide circumstantial evidence later. A game with no challenge is not a game (for the point of a game is to provide challenge), but that does not mean it is a piece of a media that cannot be enjoyed. None of what I said was meant to be derogatory but spoken as perception. You took offense(clearly) when you didn't have to.
And although I don't think both of these are directed at me, they feel similar enough to lump together.
Do you have a single fact to back that up? What game has had an increase in difficulty that resulted in a quantifiable player loss?
While I can't argue that games die because they become too easy (in spite of WoW's decline in player base as homogenization set in as well as raid finder being added) most predominantly due to lack of interest in finding correlation, I can certainly argue that adding additional difficulties has had positive impacts. Terraria, as an example, added 'expert' difficulty to it's game and it was received in a positive light. The game still sits at overwhelmingly positive (whether this is a result of the game being good or not doesn't matter because a harder difficulty was added and therefore we know it did not have a negative impact on the game).