We've always done it that way
The architecture should describe the motivations for all major decisions. Be wary of "we've always done it that way" justifications. One story goes that Beth wanted to cook a pot roast according to an award-winning pot roast recipe handed down in her husband's family. Her husband, Abdul, said that his mother had taught him to sprinkle it with salt and pepper, cut both ends off, put it in the pan, cover it, and cook it. Beth asked, "Why do you cut both ends off?" Abdul said, "I don't know. I've always done it that way. Let me ask my mother." He called her, and she said, "I don't know. I've always done it that way. Let me ask your grandmother." She called his grandmother, who said, "I don't know why you do it that way. I did it that way because it was too big to fit in my pan."