Why high-end cable manufacturers don't post measurements?

Coz it is mostly snake oil. 

Mr. glupson

Dayan was a big art (archaeology) thief. Mayby, the bigger in Israel ever.

Well, cables recommended did have a larger than common cross section.
Yes, it is a bit tricky to connect such a cable to the Amp and Speakers binding posts. But it is solvable. There are plenty of ways, most involve a short tail, of a less thick cable (like # 8 awg).
The difficulty should not be an obstacle in your way to get better sound.
Really better.
The #14 or #12 awg cables (most of them in the speakers cable market), are convenient to work with, but they do not do the job and do not sound good.

I agree that cables now play a large role in the final sound. But..does this justify the prices of some cables, Do you get value for your money? I'm not so sure. Don't know if exposing the measurements will help our decisions.

^^^^You don’t have to spend mega bucks to obtain high quality cables. There are plenty of cable brands that offers great value for your money.  Look into Audio Envy...they were the end game cables for me.