10-12 years or so ago, I had a pair of RadioShack Pro-35 headphones which were rebranded Koss (don't know the OEM model name). They played great out of the portable CD player I used them with, were quite lightweight with good mechanical design and form, and sounded pretty good as I remember (titanium drivers no less). So Koss didn't miss the mobile train completely. Below are the Radio Shack one from "back in the day" and its apparent Koss-branded descendant.


Koss is still in business but a look at their site reveals a hodgepodge of boring-looking designs, many of which look pretty much like each other. You can still buy a Pro 4AA if you don't mind taking them off to drain the sweat every so often. The Porta Pro has been around forever. The rest (especially the portable-oriented models) seems to be a bunch of el-cheapo 'meh' with the electrostatic model seeming completely out of place (it too has been around for many years virtually unchanged).
I guess every dog has his day.