Why doesn't Riot just nerf Tryndamere's AP ratios?

They are currently increasing Trynda's E cooldown at later levels. It was something they first reduced to compensate for the fact that Tryndamere no longer has easy access to CDR in an AD build, due to the rework to Essence Reaver. However, it was one of the main reasons why AP Trynda became broken, since he has easy acces to CDR.

However, it seems like just reverting the cooldown buffs is the wrong thing to do. It was meant to help AD Trynda. If the problem is his AP build, why doesn't Riot nerf Trynda's AP ratios? A better question is... Why he still has AP ratios to begin with?

I am the first player to defend alternative builds, but AP Trynda is just too unhealthy to exist. Cancerous sustain, you can't itemize against his damage (even if you build both types of resistances, Conqueror is a thing), and he is too sticky.

A better solution would be to nerf E and Q's AP ratios, so that he heals for less and does less damage when building AP. Nerfing his cooldowns will not stop AP Trynda from having cancerous healing and damage that is both too high and impossible to itemize against.