I think Eupolis is right. It goes from one extreme to another. There were groups who had ridiculous requirements (I know when my APO chapter was in its early days, if you had pierced ears, you had to wear your pin in the shower) and rightly so, those were eliminated. But now it's gone to "here's your pin....if you want to wear it you can...but you really don't have to...it's OK if you don't...whatever you want is fine..." Bleah. I feel like we're subconciously saying "treat this org and the members however you want, it's okelly dokelly doo."
Requiring pins during weekday daylight hours, I see nothing wrong with at all. Oh, and I should add, we didn't have to wear "pin attire" with our pledge pins. This might be the reason NM's are not wearing them - who wants to dress up every day for six weeks? There are many schools where the sisters only wear their pins for rituals simply because the climate/topography does not lend itself to dresses, dress pants and shoes. It doesn't mean they are less loyal, just that they are sensible.
Edited to add re the letter thing, we could wear letters from the first moment of pledging, but both my orgs had open mottoes that were spelled out by the letters and on our crests for the world to see, if they read Greek. If your letters are different from your motto - say, if Pi Beta Phi really doesn't stand for Perennially Being Friends
- or your motto denoted by the letters is secret, I can understand the prohibition on wearing them before initiation.