Actually in those photos only the karate and aikido people are wearing judo dogi. I will say that I know a lot of HNIR folks who train in neither judogi no hakama. They like samue.
Yes, I also know HNIR people who also like samue. When he does demonstrations, however, the soke wears traditional Japanese clothes, not uwagi. The same is true of many other koryu. This is contrasted with kendo, where demonstrations will be performed in uwagi. My point is that uwagi is not "traditional training clothes," otherwise it would be worn by koryu for demonstrations. So if it is not traditional, where is it from? It comes from Kano, who started a trend away from wearing regular clothes to wearing specialized training clothes. The karate and aikido people are not wearing judogi, they are wearing keikogi. The karate ones and the aikido ones are different from the judo ones, and all of those are different from the kendo, jukendo, naginatado, etc ones. But they are all keikogi, and all have their roots in Kano's design.