PBE Public Beta Testing Environment

I have a question for you riot, Why are there soo many mistake Nerf or buff that slips through the PBE? Over 100k player on the pbe testing the game balance on soo many stuff and yet soo many questionable nerf such as Rek sai hp nerf and soo many other things. The PBE is just for skins, ducks, there is no actual balance there. Have you considered taking suggestion from players on balancing champion and actually test it on the PBE? Such as suggestion like Leblanc E hitbox made thinner and her W less big of aoe, or Zed shadows expire faster under turret or less sustain from passive from cho gath or anything else?

But yet PBE Fail to Test balance of anything.

Remember there was a Patch note rundown with MissPudding about changes on Lucian E?

She tested 40% cooldown reduction on lucian E to see how Kassadin like he was gonna be yet they ignored her comment completly :/. But by the end of that patch rundown, the wave of Lucian Bolts started in ranked where he became freelo until his E was Nerfed. https://www.youtube.com/watch?v=mgKM9tYLe1g&list=PL5C21EBCCB32F15E3&index=8