My friends and I shelved D4 a couple months after launch as we realized it was D3 launch all over again. We decided to give it a year or two and come back whenever the expansion drops, as we're assuming that's when they'll fix a lot of the core design problems with the game, similar to what happened with D3 and Reaper of Souls.
I will say that we absolutely had a blast playing through the campaign together and even solo on occasions. The game has solid bones and tons of potential, but it seems like they were rushed and it didn't have enough player testing and system refinement iterations. It very obviously needed at least another year of development. Hopefully they can turn it around in the expansion/future patches, because it'd be a damn shame for what's there to just go to waste indefinitely with half-assed seasonal content.