I have a lot a game complaints and I don't even own the game. Just from watching people play the game i have noticed many things wrong with it, such as the E3 promise that "you can do anything you want", or how underdeveloped Diamond City is compared to the other areas, or how half of the cool enemies and areas that we were shown at E3 don't start appearing until you're about 4 hours into the main story, or how bland and simple the main plot is.
The first complaint about the E3 promise, they said how you can shape the dialogue and conversations are dynamic, they are not as dynamic as the two previous games as in if you chose the sarcastic option, you wouldn't say something like "yeah sure dick bag i believe that." like in FO3 or NV, you would just say something like "yeah right.", and with the character morality, there is little to none, the only people you can actually make hate you for what you've done is your followers, and even after that they will never attack you, only say "you're a bad person." then walk off, it's too simple of a system.
The second complaint about Diamond City is a simple one for me, the area is way too boxy and simple, like a maze with only one tunnel to go through, and its way too dirty and rigid looking to even still be standing, its mostly cosmetic for this one and can be over looked.
The third complaint on the cool enemies and areas, if you want to see any of the cool areas that are hidden in the game, you have to either wait until the main story is 90% done and see them naturally, or you can go as far away as you can from the main path and search them out in places 30 miles away from where the game wants you to be. and as for the cool enemies, you will have to either wait until you're high enough level to actually fight them, or go out of your way just to see a cool variant of a deathclaw in a heavily radiated area that you shouldn't be across the map, its just too hard to wait before you'll actually see any non-bland areas, it would just be better for you to wander around until you find something you like.
As for the last complaint, the main story line, it is way too simple and least magnificent since fallout new vegas', and at least that game was still fun, The Institute for one is depicted as a deadly menace that will never die no matter what, but actually they are completely powerless if some pissed off parent decided to bring nuclear weaponry into your base, and as for the starting motive, the baby being stolen, its a budget movie-like plot device, you would be better off avoiding the main plot for as long as possible.
In conclusion, Bethesda hyped the game too much for what they actually gave us, I might be wrong about a lot of these since I don't own the actual game, but just by watching the game I noticed these things, Bethesda should at least give us an option to have a silent protagonist with clear options for dialogue.