spp85 :
For answering "Why", simply speaking i5/i7 is much faster than FX8350 on not just gaming but almost everything at much lower power consumption. Just Google about some benchmark and you will convince yourself
In stuff like rendering, the FX-8350 can get surprisingly close to the Core i7, and beat the Core i5. As long as the software is well threaded. Singlethreaded performance is the Achilles heel of the FX-8350.
HEXiT :
in games theres little to no difference if you get 50fps with a i7 4770k and a gtx780 you will get 49 with the amd 8350 on most titles and on some you will get better gaming performance.
There are quite a few games that are partially or predominantly CPU-limited. Skyrim falls in the latter category (and heavily favors Intel), Crysis 3 in the former.