"We're trimming some single-target potential off of Ahri's auto targeted spells..."

Ahri is outperforming most midlaners due to how broad her strengths are. We're trimming some single-target potential off her auto-targeted spells so she’s more reliant on landing skillshots to secure kills. - Patch 7.11 notes

If this is the case, why did you reduce the ratio on W rather than increasing the damage reduction per Fox Fire that hits the same target, instead of also nerfing her multi-target damage as collateral damage?

Is it because the damage reduction would affect her base damage on W as well?