Fallout 76 Hands-On: 8 Reasons You Should Be Worried
2. No Real Objective
Yes, your main prerogative is "Go reclaim America!", but that's an overarching, never-ending MMO "main quest" if I ever heard one. 76's story is more routed in the relationships you'll have with other players, or "that one time you teamed up to defeat Mothman".
It must be said that every time a developer falls back on the "our game's story is told by the players" shtick, it never goes well. Although VICE's Motherboard site houses a great piece on how environmental detail can create a riveting playspace to explore, it's nothing on the "find your father", "avenge your failed execution", "find your infant son" setups of Fallout 3, New Vegas or 4.
Clearly, this completely non-linear setup is geared towards longevity, and possibly tiding us over until The Elder Scrolls VI drops. That said, a Fallout game entirely based on "Just go find things... there'll be something out there... somewhere!" is going to divide a lot of people.