No, it's not. But it's super easy to digest cause there's nothing to think about, so of course a lot of people play it. I play it too, avidly, and keep hoping there's something more to it than just gunning my way across the wasteland. And to make a comprehensible list of everything I need to mod.
I love Fallout, and I will probably keep playing Fallout 4 for quite some time to come. Graphics are way better than FO3, obviously, and it actually runs smoother than Skyrim did for me, so it's sort of a good mix. I just wish it was actually interesting, but that's where mods come in.