I don't get ash

A long ash keeping the cigar cooler has never been proven or disproven to my knowledge. As mentioned it is all about perception (which is the case in most of this glorious hobby).The concept is that the ash acts like a radiator to help pull heat away from the cigar as well as a reduction in the oxygen that is needed for combustion of the tobacco.

Try it with or without long ash and see whether you can tell the difference your preference is what matters.