Lots of good responses here, but I think it was JHN(?) who hit the nail on the head: the market for revolvers just isn’t big enough to get much attention.

That’s pretty much across the board with durable goods. Companies make as good of a product as the market demands.

The great “quality crises” that hit Detroit in the ‘70s wasn’t due to a significant drop-off in quality. It was because cars started being financed longer than 36-months. Then the market started demanding better cars. So long as consumers were happy with buying a new car every 3 years, there was no incentive to build them to last longer.