Watch dogs CPU performance:
http://www.techspot.com/review/827-watch-dogs-benchmarks/page5.html
Notice how there is absolutely no difference between the 4670k and even the really high end i7's? Notice how the dual core i3 almost catches the 8 core 8350? Who ever told you it doesn't run was lying.
Also, it's not that the 4690k is the best for gaming, the i7 is clearly a superior processor. The problem comes in when you add in a budget and the question becomes "At what point is your processor good enough that you should shift to spend money on your video card over your processor". Since generally the i7 is good at 'work' stuff and the i5 is nearly as good at 'gaming' stuff the generally held belief is that you should get the i5 for a...