"When REI is so stupid that they do not mention the weight of the product, I simply won't buy it. Pretty soon you would think that they will learn that there is a small community of UL backpackers who might have been interested in such a product, but ignoring the weight issue simply causes us to shop elsewhere."
I have found that they often do not show the weight specs on running gear, but usually do on "backpacking & mountaineering" gear. But to your point, I do have some of their running tops I use on my hiking trips. I wore one of their OXT Airflyte Hoodyies on several trips last winter.
I am more irritated that many of their stores don't have scales. The Torrance store had one years ago when I lived there.
Last year I was in their Las Vegas store, and they looked at me like I was some sort of a zombie when I asked for a scale to weight some stuff.