It's well acknowledged that a man usually fights well when he has a strong sense of primary group. This manifests itself as current group, the men on his left and right, and historical group, those who've gone before.

Most people are capable of being moved emotionally by simple banners and symbols and a shared experience. Witness a shirtless, painted up idiot in freezing weather rooting for his NFL team. Gang violence over colors, symbols, and turf is another example.

To the extent that D&C can instill and reenforce a sense of primary group it remains a good thing.

Regimental days, parading in memory of some past deed of valor performed by a former member of the unit, can instill and reenforce a sense of primary group.

Retirement ceremonies do not.