Originally posted by andrew
I gather that the strict policy stopped in the postwar period in Japan because there simply happened to be a cloth shortage. People were turning up to classes in expensive silk hakama that had belonged to their Grandfathers and destroying the knees.
I heard a similar story. For what I've been told, before war, everybody was wearing the hakama. It was the normal training suite. However, after the war, the japan was in a bad economic state and many people simply couldn't afford the luxury to buy an hakama. So, O'sensei decided that the hakama may only be worn at yudansha level if people couldn't afford one sooner. He simply didn't want to see promising aikidokas stop training simply because they couldn't buy an hakama... Don't know how much of that is true but it certainly make some sense...
From that, it somewhat degenerated in an hakama=yudansha thing... However, this equation isn't true in many organisation or dojo. In my dojo, and all other dojos in town, people are allowed to wear hakama from the 3rd kyu if they wish too. But there's no obligation to wear one...