Gamers these days are just impossible to please. We are spoiled with great games and there is always someone who will find something to complain about no matter how great the game.
Because not everybody likes the same things, so a great game for you might not be a great game for someone else. And the games you don't like or think are bad are liked by other people. Yes, including that terrible one that's really awful and shit tier. Different people value different things. Like, if you go to the worst movie you can think of, it probably doesn't have a 0% on Rotten Tomatoes, because one or two reviewers actually liked it. And if you go to your favourite movie, or the greatest movie ever made... some people probably didn't like it. It's OK.
And it's not like the same amount of people complain about everything. The way we form a consensus about things is the relative strength and number of voices on each side. When someone says it's commonly accepted that Watchmen is a great graphic novel, or that The West Wing was a great TV series, or that the Beatles were a great band, it's not because literally every single person on earth accepts those things, it's because many do and over time that's emerged as a sort of consensus. It's OK if you're a part of the consensus. It's also OK if you're not.
It surprises me that people continuously express incredulity about how "there's a hater for everything", as though there are Games Sent Down From Heaven On A Cloud Of Rainbows, Praise Be To Reagan or whatever.
I agree, but is an iterative concept which happens to be executed extremely well just an inherent negative for these folk?
The reaction to the example you've chosen, thusfar, appears to be that it's not particularly iterative, and it's not particularly well executed. That's the substance of the criticism you've identified. If you agree or disagree, whatever, but that's what people are saying. No one is saying "This looks amazing but I hate it because it's not new enough", they're saying "This doesn't look amazing in part because it's not new enough." Surely you can recognize that some games are iterative and are praised for it, others are revolutionary and praised for it, others are avant-garde messes that are criticized for it, and others are derivative and criticized for it. There's no particular trend of people demanding new; quite the opposite, in fact, people's purchase and award tastes are remarkably narrow and iterative and mostly the gaming community, including GAF's, aggregate reaction to something is to reward familiar but improved ideas.