In my humble American opinion I think you have it right on the money in your opening post. Americans tend to be much much less subtle in showing their pride when it comes to military service or alma mater. Personally I like the idea of the tie but usually here, when someone wishes to be subtle, you see them with a ring (class ring, military service ring etc...) The tie is one of those really cool cultural things that I'm sure most Americans never heard of (I know I hadn't until today).

Mike