Deoxys-D was one of the most popular Pokémon to use on weatherless offense teams. Without something that can immediately put the pressure on opposing teams that utilize weather, these teams would see a lot less use, and I could see the metagame centralizing even more around Drizzle, Drought, and Sand Steam. (lolhail.) I personally hope the extra centralization is enough to give the boot to these abilities (haters gonna hate) but either way, this does slow down the metagame a bit. No more instantaneous 3 layers of hazards, or 2 layers of spikes and screens.