Fallout 3 was obviously a major change from Fallout 1+2, and so a lot of older fans were outraged over how different it felt, but the differences are somewhat understandable given how long it had been since Fallout 2 was relevant some of those changes were simply a matter of updating the game for a more modern audience. And when you buy a game called Fallout 4, you expect that it'll be like its predecessors.
Unfortunately, this isn't some other game - though it may play differently, it's still called Fallout, and is still therefore a Fallout game, supposedly.