Hextech units are strong enough, they don't need an OP synergy to be effective
How is any itemless comp (other than nobles +draven/jinx) supposed to respond to jinx/vi mowing your team down. The top 2 finishers in every damn game have at least one player, if not both, running 2 star jinx with hextech synergy. The comp is so blatantly strong that players caught on within a day of the patch release. Something so broken should have been quickly been identified during testing.
Jinx/vi need a nerf and either the 8 second duration or the item cancellation radius of hextech needs to be reduced (or the synergy benefit needs to be changed altogether).