It the Graves nerf really that bad at all?

Nah, it didn't hurt his burstiness. If you all in (slide in and buckshot), you'll do just as much damage. It's only his long range "try to hit them with the tail end of Q without getting hurt" that got nerfed. It's playing up his strength while exaggerating his weakness.

It's not so much a nerf as it is a power shift. TLDR his burst and trades are stronger, but his "long" ranged harass is worse. Which honestly doesn't matter that much since he is so damned mana hungry that he can't afford consistent harass anyway.

Side note: Gods I want Essence Reaver to actually be the item we were told we were receiving.