I agree with you in the sense that it should not matter. Where we disagree is that you feel the issue is (or should be) trivial and irrelevant for everyone, and I feel that it is trivial (though never irrelevant) for some. What matters to me is that we should all respect one another's choice, though the final word goes to the sensei because in the end, he will teach you valuable lessons that go beyond just connecting to symbolic virtues. Some feel that the hakama is unimportant for non-yudansha...then so be it. If the sensei feels this way, it is his rules, but then he has shown he has gone contrary to what the hakama is supposed to represent. Again, that is fine as it is his belief. But in the end, I would prefer a sensei who respects these traditions, for it would make me feel as if he is more open minded. It's not about the sensei disrespecting me because he doesn't feel the same way I do, but rather on the reasoning why he feels a student should not also be connected to tradition (which technically is going against the wishes of O-sensei).
As for where I got the notion that the hakama represents the seven virtues of budo, this comes from Mitsugi Saotome sensei's book, The Principles of Aikido which was written in 1989. In the book, Saotome Sensei says that it was O-sensei himself that attributed the 7 virtues to the hakama because there are 7 pleats in a traditional hakama. In a way though, O-sensei could be considered modern, so the people who said it is a modern attribution to the hakama are not incorrect. In the book furthermore, O-sensei required all students even if they were brand new to wear the hakama precisely because it represented the ideals of budo. As a side note, I found this very intriguing when I first learned of it, since I had never heard of it nor had the 3 yudansha at my dojo.
About reality. Ghandi said, "we must be the change we wish to see in the world". Is not the whole purpose of aikido a selfless one about trying to get the entire world to act in harmony? I believe that if we see aikido as a means to our own personal peace and salvation, then we lose the greater picture. In a way, it is the difference between Mahayana and Hinayana Buddhism. In other words, we should not settle for what constitutes what goes on as reality if it is against a harmonious nature. This is the true war that we face I think.
Unfortunately egos are egos as you pointed out. I'm still trying to figure out how to get rid of mine.