There aren't a lot of things a guy can say to really support the notion other than it's just tradition. However, it's kind of important to have one name per family unit. I'm not going to have children who do not bare my name, and I will not have children who do not bare the name of their mother either. "Hello Mrs. Findley, I see you're here to pick up Wesley Senger, are you his legal guardian?"
Merging names is also a stupid concept that I wish would go away. Ok, so you want my children to be named Senger-Whatever, it looks dumb on paper already, and what do you expect them to do when they get married? Are we going to have a bunch of Senger-Whatever-Yadda-Yaddas grandchildren running around? It's a retarded concept, and if it really caught on, we would have names that take up an entire paragraph. Unless of course somebody opted to just sacrifice their name or something, that would work, and it does work.
One name per family, it works, it makes sense, let's keep it that way. The way I see it, it's a conflict that is bound to come up, who will give up their name, well the tradition is easy to follow and eliminates that problem. Oh, and when I said I didn't have anything to say to back up the tradition, I didn't say I had nothing to say. The man is the head of the family, there is no disputing this. It's a biological gender role, women take care of the children, men hold the fort. You don't see men taking paternity leave while the mothers go to work and feed the family. We are the head of the family, the family is in our name.