MASSIVE nutpunch-level nerf/gutting of Thornmail on PBE!!!

UNIQUE Passive now reflects 15% of damage + 25% of the user’s bonus Armor, changed from 30% of damage
APPARENTLY it isnt enough that ADCs are the ONLY required class, nor that you MUST have a ranged ADC to siege towers or take objectives reliably.
All must bow before the ADC overlords. NONE may be allowed to survive their damage. Any teamates exist only to protect and support their ADC masters and bask in their radiance
If you do the math, even with 200 bonus armor this is a WHOPPING 30% nerf vs crits against an AA based ADC like ashe/cait/jinx with 300 AD and IE/PD. You wont break even until over 400 bonus armor. ** OH WAIT THATS BEFORE YOU GET ARMOR SHREDDED BY UBIQUITOUS BLACK CLEAVER OR CHAMP ABILITIES. So in reality you would need 600 bonus armor factoring in a 30% shred JUST TO BREAK EVEN with current Thornmail**
The only ADC who do significant on-hit damage are vayne and koggy. This change is at best a wash against them.
TL;DR: The one item in the game that had some measurable countering effect on ADC is now nerfed into oblivion. It provided NO health, NO magic resist, NO offence whatsoever. It was a sacrifice of an ENTIRE item slot just to marginally challenge ADC using MOUSE2 on you and destroying you even if you were a tank.
Welcome to the league of ADCs
Bonus math section!
ADC with 300 AD from IE PD BT LW BOOTS GA 300 AD, 55% CRIT (almost exactly 5/9)
TANK with 200 BONUS armor
9 attacks 4 NONCRIT for 300 apiece, 1200 subtotal 5 CRIT for 750 apiece, 3750 subtotal 4950 total raw dmg.
95 returned noncrit with new TM, 380 subtotal 162 returned crit with new TM, 815 subtotal 1192 TOTAL RETURNED WITH NEW TM
OLD TM returned 0.3 x 4950 = 1485
1192/1485 = 0.8
20% NERF TO DAMAGE RETURNED VS STANDARD ADC BUILD COMPARED WITH OLD THORNMAIL
WITH 12% CRIT FROM RUNES, BECOMES A 24% NERF
did you say armour nerf?!?!? Proceeds to drowl.