I don't find the use of my letters trivial thing either. I know that I personally would not wear letters on my rear. Also, I know in my chapter that it was highly expected of you to be presentable when wearing your letters. Walking around campus, hungover or sloppy messy hair/makeup, was highly discouraged and looked down upon. I think most chapters are like this though. 'Big Brother' is always watching....especially when one has on their letters. I know if I saw an XYZ being unlady like per se or acting like a fool, the letters were the first thing I noticed. With all that being said, I think that the use of your letters is something that one should respect and think twice about before they use/wear them.

just my opinion