Why it is so difficult to find a hifi power cables from IEC-C14 to IEC-C13 terminal?

Hifi power cables with terminals from IEC-C13 to CEE 7/7 (shuko) seem infinetely more abundant than with terminals from IEC-C13 to IEC-C14. Why is this? I have 3 Furman power conditioners, including a great AVR, and they all have C14 outlets in the back. It would be nice to experiment with better power cables between the Furmans and my recording studio audio devices. These cables seem very hard to find though. Especially in angled formations. 

Am I missing something? A lot of hifi enthusiasts like hifi power cables AND power conditioners, so one would think you could get a decent selection or C13/C14 PC:s in the market. Or does the PC quality matter less when it's plugged into a power conditioner instead of a regular wall socket?

Looking for: 

a) Theoretical background info on why there is such a discrepancy on the market;

b) Tips/recomendations of brands or vendors who offer these;

c) Insight of whether I would be better off making my own with good components.

Thanks!