I agreed with everything in your post. Earlier today I came across a post by a user (joab777) on N4G that described how impossible it seems to satisfy people lately.
Well, yes and now. The problem with many mainstream games nowadays is that they don't have a core democracy and a "clear focus" anymore. They want to be attractive for as many people as possible and therefore they have to offer different things. The problem with that approach is actually quite obvious. Many people likely don't like everything the game offers.
I make an example: the Souls game and also Bloodborne. These are games made with a clear focus and two or three main components (mainly combat system). These games are made for a very specific audience. So you usually either love it or you're just not interested in the genre/type of game.
The same is a lot harder if we talk about a game like Witcher 3 because this game has many aspects and it's quite natural that you like some of them while you dislike some of them. So you perhaps like the open world design but hate the combat system. Or you hate the open world design but like the story-driven approach with the concentration of choice and consequence. Of course there might be some people who love almost everything planned for the game and I'm happy for them. But I think people should respect different opinions as well from people who are not completely happy with the game, not because it offers too little, but too much! That might sounds crazy when you hear that for the first time, but that's how it is.
Game design is all about choices and some choices lead to elments in the game not everybody likes, no matter how good they are in theory. For example, the open world might be the best ever created. Still there will be people who won't like it very much. Similar is true for the size of the game, in both hours and map size. What sounds perfect in theory might be disliked by some and they possibly have good reasons for that, maybe because they don't like travelling much of the time, becuase they have only little time or maybe because they prefer playing a more staged game. At the same time it's very possible that they like other elements of the game very much, e.g. the art design, the combat, the story. So it's not that easy to say: "Hey, you don't like design decision XYZ, just play something else!" That's exactly NOT how big mainstream games work nowadays because almost everybody likes something in the game and almost everybody finds something to get excited about. But it's imo really hard nowadays to love the whole package of such a game, at least in my experience.
So while many of the complaining might be just pointless internet chatter there is some truth and some deeper sense behind it. Just think about it.