John Mulaney has admitted that this show didn't work out the way he hoped.
However, he is funny enough that even his worst effort is better than a lot of syndicated sitcoms.
I gave it an 8. I'll be the first to admit that is extremely generous. I was disappointed when I watched it the first time, but I gave it a second shot after it got cancelled. High expectations are a huge reason (I think) that so many people hated this show.
I also gave it an 8 in the hopes that that will encourage someone to give John Mulaney a chance at redemption. I think he'd do a better Netflix, Amazon, or HBO one hour drama. I think maybe some combination of the NBC platform and the sitcom genre took this show down in quality.
Still, if you're a John Mulaney fan it is worth watching at least an episode to see if you like it. Don't be too put off by the low star rating.