Essence Reaver, too much CDR?

Perhaps i am wrong here, and if so please correct me, but does really give CDR at a 1 to 1 rate for additional bonus crit? If this is correct, does anyone else feel that's kind of bullshit? I mean i know Riot really wants ADC type characters to be part of the CDR crowd (i think it's really stupid to give a class that usually functioned with little to no CDR, the ability to max out on it without changing the base cooldown of their abilities but that is a different thread all together.

Anyway, Assuming it is in fact a 1 to 1 ratio. Is it possible to change it to something like a 2 to 1 or even 3 to 1 ratio? So that instead of having Reaver + and BOOM 30% CDR, the champion has to build more crit to get the cooldown reduction bonus. Chances are the players will still build items that increase their crit to 40% or more, this simply moves the time table back so that their max CDR shows up around items 3 of their build (not counting boots) instead of item 2.

Edit 1: So did a custom, apparently its more then 1 to 1 but less then 2 to 1. got Reaver plus & and was rocking 30% CDR.