It never even occurred to me to compare Fallout 4 to Skyrim. Maybe that is a good place for OP or anyone to start? Consider that, its an apples to oranges comparison and why would you compare the two?
Would you compare the fun of shooting an RPG-9 to the experience of drinking your morning coffee? Both might be fun, but they are just totally different. Not saying Fallout 4 and Skyrim are _that_ far apart but they are quite a distance along that continuum.
As far as, loving and criticizing, my only beef with some people's opinions is that they are ill-informed and locked up. Just as an example, someone starts a thread saying "There is not enough content," and claims to have "finished" the game in ~50 hours. Moreover, when people try to examine their claim with queries about the specifics of their playstyle and/or suggestions on what they might do differently to get more mileage out of the game, this sort of forum user (and there have been at least a couple dozen if not scores over the 10 weeks or so) then becomes defensive, passive-aggressive, and argumentative, and begins accusing those who try to interact rationally of being 'overly devoted fans' or 'corporate stooges' or whatever. Any thread that is either titled with a blanket statement of praise or criticism is likely either playing on, or playing to this dynamic that has been so common on these boards since the game was released.
I suspect that many might think of me as some sort of 'defender' of the game, but if you actually read what I write, I have expressed many criticisms of the game. It has many deficiencies and some quite nagging flaws. But then again so does a brand-new Mercedes Benz. So does every masterpiece, except perhaps those which are so specialized that their functionality is easy to perfect.
. . . I wouldn't bother to prattle on about this, except that I see this same trend as being fairly predominant across global culture today: polarization, hyperbole, exaggeration, partisanship, opinion in the absence of critical thinking, dogmatic if not self-serving views . . . no doubt these have always been a part of human experience, but I fear their 'fashionability' and frequency have increased measurably in my lifetime and it is a trend I find unsettling. Even Universities themselves are guilty of it, indeed, some have claimed they are engulfed in a wave of dogmatic indoctrination that is totally at odds with the traditional them of the liberal arts education, which is to promote critical thinking and good general knowledge base.