MB nailed it, especially in his last paragraph. To me, any conscious descision to save weight is a step in the right direction. A few years ago I was at 50+ lbs for a summer weekend trip. Two years ago I totalled about 40 lbs. This year I aim to be under 30 total (camera gear, bear vault, consumables, etc.) In my mind these are big improvements in a hobby. Some new gear has obviously contributed, but honestly mindset, comfort zone, and better planning have contributed even more than a change in gear to the weight loss.
I'm a long ways from being a UL backpacker, but I'm firmly of the belief that improvement is a good thing, and if a number helps set the goal and make it achievable, then the number is a good thing. If it is simply a number for it's own sake, without taking needs and wants into accounts, then it has a lot less benefit to me.