Totally false, of course, as is typical of Eden's posts here. He doesn't even know what the majority of the fans think of FO3. No one does as no research has been done on the subject. However, if we use the business success of the game and the overall reactions of industry personnel, critics, and consumers, we can easily see that the majority of people loved the game regardless of the qualities of the story or combat or any other factor that someone might focus on.
I'd suggest that any so-called "fan" who thinks that FO3 had a poor story may want to debate their viewpoint with Liam Neeson who stated that the story was "very good" and who has far more experience in evaluating such works than general consumers/players. Such "fans" may also want to create their own game with what they consider a superior story so that their viewpoint of what is superior can compete with Bethesda and others in the industry who actually work in this particular field. If they do not undertake such tasks, they surely have no grounds whatsoever to claim that FO3 or any other story in any game is somehow lacking, not as some type of objective fact or observation as they almost always claim. They are certainly free to state that a certain work wasn't their preference as that is merely voicing their opinion. That is entirely different than what we usually see posted here and many other places, though.
By the way, FO3's story had nothing to do with "a quest to find daddy". It was a quest to bring pure water to a war-ravaged wasteland, but that's only assuming that you roleplayed a character who actually took up that particular quest. Claiming that it was "a quest to find daddy" is like claiming that Oblivion's story was "a quest to find the Joffery and deliver the Amulet of Kings".
As for OP... FO3 was dark and serious, yes, as it was intended to be. However, it also had plenty of dark humor as Fallout has always had. FO4 hardly seems like the Sims in any way. Sims is a totally different type of game for a totally different audience/market. Closer comparisons can and have been made such as comparing FO4 (what we know so far, at least) to the original Bioshock (which was also very dark with very dark humor).