Yeah, I agree with Sun Genesect. It's weird but I feel more inclined to blame Dugtrio more than Genesect. Genesect on its own I can handle, but automatically losing Terrakion can be a bit much (I tend to either run Rotom-H or Shed Shell Heatran otherwise).
Drizzle Offense is definitely the dominant play style and rightfully so. It's difficult to approach, though, as a Drizzle ban entails so many other things. Drought offense would become (even more) ridiculous without Drizzle, so it would probably be banned too, and you lose yet another play style as a result of that.
And yet, you can't address the balance any other way. It's not as if you can introduce a Drizzle + Genesect/Tornadus-T complex ban, as making yet another accommodation for Drizzle at that point just becomes ridiculous.