If you looked at leaked Nvidia slides,they were bitching and moaning that newer processes were too expensive,and making it not cost effective quickly moving onto new nodes.
Hence,you saw the "small" die GK104 appearing in retail nearly one year before the GK110 based Geforce Titan(which had a massive price),and even the GK110 based compute cards appeared 6 to 9 months after the GK104.
On top of this Apple,is now moving onto using TSMC(instead of Samsung only) and they need massive capacity,so will pay for early access to 20NM. So will Qualcomm. These companies dwarf AMD and Nvidia in purchasing power.
Edit!!
Here are the slides:
http://www.extremetech.com/computin...y-with-tsmc-claims-22nm-essentially-worthless