Last Whisper Builds, Please Nerf 45% AR Pen

Look, I get it. ADC's need kill power and sustain. But 45% is over kill. Then LDR give 15% Bonus DMG. And Grievous Wounds is basically the anti-Mundo. Quick search tells me that even my runes count as bonus armor. So even champs like Rammus and Braum who have over 100 base armor at 18 are crushed my this. Between this 45% Pen and Crit, a tank last about 3 sec in a 1v1 with an ADC when both are full build. Even when I am sitting on 350 total Armor and about 3500-4000 Health. These item take every Tank item I get and cut it in half. I don't find it balanced that one single item can nurf all mine by 45%. Then you add Battering Blows for another 7%, and say Youmuu's Ghost Blade for another 20 Pen. Here is some math.
100 Base Armor 100 AR Thorn mail 50 AR Sunfire 65 AR Ice born Gauntlet 20 AR from runes =335 AR w/ 235 as Bonus. 235 + 5%(Unielding) = 246.75 +15 (Legendary Guardian) Total 361.75

246.75(Bonus) - 45% = 135.7125 + 100(Base) = 235.7125 - 7% = 219.212 - 20 = 199.212

361 AR reduced to 219 with one item and a mastery. Not even much need for

But don't forget the 15% bonus because I have 3000 Health. BotrK for 6% more of my health. Crit at like +40%. You've now turned a big ass tank into a squishy mid laner who will last 2 seconds front line in a team fight because they don't have the sustain of life steal (which is annoying and op).

Keep in mind as well that only 21 champs have over 90 base armor. and 75 champs have 89.9 to 80. So that 100 base armor was generous. And any armor you add from masteries is cut by 45% as well.

I figure I'll get some ADC mains here crying. So let me say this again. I get it and ADC needs killing power and sustain. But when you take a champ like Udyr, Mundo, Zac and 1v1 them with Vayne, Cait, Luc, Kalista and they don't have to do much more then stand there and auto attack that's just wrong. That's if you can actually lock them down and do so with Luc speed boost, Vayne rolling every 2 sec, Kalista hip pity hopping around like fucking peter rabbit. Ok Ill stop here. Math maybe rough I redid it to add tank masteries in to be as fair as I can. Even though Mortal Reminder and LDsR is not.

Edit: I found the old Last Whisper. 40 AD, 35% Flat Pen applied first. So Lord Dominick's is way stronger then that in the situation above with 40 AD and it's full 15% over all DMG boost. And Mortal Reminders situation use to crush tanks with health regen. I am start to think people that are crying for the old last whisper haven't crunched the numbers to see that the new LD's is significantly stronger. Also considering most Mages build Rod of Ages, Rylia's, or Liandry's. Which will end up giving you the near full 15% DMG boost of LD's.