I get nerfing lethality Varus, but this nerfed crit as well...

Riot recently lowered the damage on his Q and increased the CD by 4 seconds, but they made it so when he autos someone stacking blight stacks then hits them with Q the CD will decrease by 4 seconds(effected by CD reduction), as opposed to a lethality Varus never even touching AA range and just sniping from fog. So if he builds as a crit adc I thought he would be able to lower the CD by 5 or 6 if he were to hit a blight stacked target, essentially lowering the CD of his Q (From what it originally was), but only for those that got in AA range, (AKA crit Varus), but that is not the case. When you get cdr the 4 second CD reduction doesn't increase to 5 or something, it decreases to 3.6-3.2 or w.e. So what I was thinking was a smart buff to crit Varus and a nerf to lethality Varus just actually made both worse, but lethality a bit more worse. Therefore, if crit Varus was not really that viable before, how exactly does this change, which is a decent nerf to crit Varus, make crit more viable?????

What should have been done is, the CD would still be increased by 4 seconds, but the cooldown reduction would decrease by 2,4,6 depending on the amount of blight stacks he stacked on an opponent. This would make it even harder for lethality Varus to cheat the system by AA'ing one time then using his Q, while rewarding Varus for building attack speed. At the moment if you build AS on him the problem is it also lowers the damage of his Q, which makes people reluctant to build it. However, if he could shoot Q's more often for building attack speed, that problem would be fixed and AS Varus would be a good pick, especially late game.