What this is going to do with 100% certainty is pigeon hold players to specific builds. Builds that used to rely on handling the initial brute force damage through use of items (Guardian Angels) are ripped apart within 1 second... Kennen is no longer useful not only do you maximum get 1 to 4 on any average game... but now you can't use GA on him for example...
This will force players to basically aim for 6 bruisers to be able to handle the health needed to tank the walls, and then hextech to nullify the other teams items... basically throwing 1 bad item on the front line of your team, and stack the rest of the items in the rear.
This is such a TERRIBLE design choice and I am not going to be playing this game until this is resolved and you sort this out. This should NEVER have made it out of testing.
I'm positive resident trolls will come and tell me how wrong I am or whatever. So go hard boys.