Made a search or two here on Aikiweb. You'll find that many people dismisses this 'seven virtues' stuff as a fairly recent invention.
Many people do dismiss such things. According to the following account, however, it doesn't appear as if it is either new or dis-missable. At least, I won't be. In my dojo everyone is required to wear one at 6 months. They can wear one before if they have my permission. If they are too expensive for folks, we have loaners.
The following is an excerpt from Saotome Sensei_
This was only the first of many scoldings I was to receive from O Sensei. However, my ignorance on this occasion prompted O Sensei to lecture his uchi deshi after class on the meaning of the hakama. He told us that the hakama was traditional garb for kobudo students and asked if any of us knew the reason for the seven pleats in the hakama.
"They symbolize the seven virtues of budo," O Sensei said. "These are jin (benevolence), gi (honor or justice), rei (courtesy and etiquette), chi (wisdom, intelligence), shin (sincerity), chu (loyalty), and koh (piety). We find these qualities in the distinguished samurai of the past. The hakama prompts us to reflect on the nature of true bushido. Wearing it symbolizes traditions that have been passed down to us from generation to generation. Aikido is born of the bushido spirit of Japan, and in our practice we must strive to polish the seven traditional virtues."
Currently, most Aikido dojo do not follow O Sensei's strict policy about wearing the hakama. Its meaning has degenerated from a symbol of traditional virtue to that of a status symbol for yudansha. I have traveled to many dojo in many nations. In many of the places where only the yudansha wear hakama, the yudansha have lost their humility. They think of the hakama as a prize for display, as the visible symbol of their superiority. This type of attitude makes the ceremony of bowing to O Sensei, with which we begin and end each class, a mockery of his memory and his art.
Worse still, in some dojo, women of kyu rank (and only the women) are required to wear hakama, supposedly to preserve their modesty. To me this is insulting and discriminatory to women Aikidoka. It is also insulting to male Aikidoka, for it assumes a low-mindedness on their part that has no place on the Aikido mat.
To see the hakama put to such petty use saddens me. It may seem a trivial issue to some people, but I remember very well the great importance that O Sensei placed on wearing hakama. I cannot dismiss the significance of this garment, and no one, I think, can dispute the great value of the virtues it symbolizes. In my dojo and its associated schools I encourage all students to wear hakama regardless of their rank or grade. (I do not require it before they have achieved their first grading, since beginners in the United States do not generally have Japanese grandfathers whose hakama they can borrow.) I feel that wearing the hakama and knowing its meaning, helps students to be aware of the spirit of O Sensei and keep alive his vision.