This is my thinking as well. However, you have several 2nd teamers playing a lot. Also, you have the nickel and dime packages starting a lot. So, what, you give out like 16 or so blackshirts??? Then they lose their meaning.
Maybe this is why Bo doesn't like it. You either have to give them out to a ton of players or you don't have a "team" mentality to defense. When someone who isn't a starter steps in they are suppose to play like a starter. No exceptions.
Maybe they are done. It would be sad to lose this tradition, but it is what it is.