I think the rise of people taking things like Cinemasins 100% seriously has made folks more nitpicky.
Plus we are currently in the middle of an outrage culture movement and an anti-fan thing (people being proud of the fact they don’t like something that is popular.)
The internet is a weird place, but I do think we are losing the ability to just sit back and enjoy entertainment warts and all.
There should be a middle ground, but I rarely see it. Most fanbases seem to want to be miserable. The Marvel community is one of the few that don’t seem to lose their minds like this.
I think that you rarely see a middle ground because you choose to not see it, to be honest. You're on one extreme and you seem to take those who don't see things your way as being on the other extreme. You characterize people who have criticisms as being "miserable" and upset over "head canon." When people have a problem with the show, you try to turn it into a problem with
them. You seem fixated on judging the people who judge the show.
You mention that the Marvel community is different. Why do you think that that fan base isn't very critical? Is it because those fans are just more level headed? That doesn't make sense, since they're not a distinct group of people. Most are fans of lots of other things. I bet that a lot of fans of GoT are also fans of Marvel, so why is it that the same people are highly critical of one and not the other? Isn't the simplest explanation that the content of one has been consistently meeting expectations and the content of the other has been falling short? Do you not think that Marvel fans would sour and get very loud and critical if the quality of that universe were to decline?
Another example is Star Trek Discovery and The Orville. They both cater to the same fan base (Star Trek fans), so why is it that so many people hate one and love the other? Is it just because they're fickle or is it because one has good writing and gives them what they want out of Star Trek and the other doesn't? Another example is The Simpsons. The same fan base that adored the show for over a decade has been trashing it for over a decade. Did the fans change and simply lose their "ability to just sit back and enjoy entertainment" or did the quality of the show change? I could go on.
It's perfectly fine if you disagree with people who think that the writing on this show has gone downhill, but the way that you continually dismiss it by flipping it around into criticism of the fans and commentary on society is as misguided and tiresome as the few actual rants, to be honest. Between the extremes of those criticizing everything and those defending everything, there's a lot of "middle ground" that still enjoy the show but also feel that it's slipped, and that sentiment doesn't deserve to be dismissed so that someone can weave a narrative about how fickle and miserable the fan base is, IMO.