I do think there's a pretty big difference between comparing every detail of a movie to comics canon, which can indeed be annoying and misses the point of an adaptation of original material, and feeling like an adaptation missed the sort of core essence of a character. Then it becomes, "Well, that's not really the same character, and the movie kind of misunderstood the very basics of them." There's an idea that certain aspects will remain consistent across adaptations.
I think Guardians is a fun movie but not actually a great adaptation of several of the characters in it. I don't go around telling people it's awful because of that, but I do tend to rate it lower on my list of Marvel movies than a lot of folks for whom it's one of their top ones. I don't really think I need to "lighten the fuck up" over that, because it's not like I'm actually making that huge a deal over it. And I don't think it's so terrible that there may be comics fans who really don't like how they portrayed Amanda Waller, who has a lot of fans due to her intense awesomeness. People want characters they love to at least be recognizable in some core manner.