I to have this problem. I have a late 2013 Macbook Pro 13inch with Retina display. I soon discovered on my machine that if you disable Bluetooth then the macbook connects to the wi-fi as it should. I dont have a problem on my home network with any other apple devices and the connectivity issue is the same on what ever network I try. I soon realised that if I disabled Bluetooth the machine connects perfectly everytime. There is clearly a bug or some technical issue that occurs preventing wi-fi connection when you have Bluetooth enabled. Try it and see if it is teh same with yours?
I was hopeing that the fault or issue would be fixed with the latest OX update but alas it is still an issue for me on my machine. I have just taken to switching Bluetooth to off until I am connected and then just turn Bluetooth on if I need it.
Hopeing that some kind of fix will be issued soon.
Let me know if this Bluetooth issue is the cause of the issue as I woudl be interested.