Personally, if I was ever in a position to have kids, I really wouldn't want them to have my last name. I just feel the sound of it is a bit dissonant and harsh. There are a lot of last names I would not like to have. Names also can be rather ruined by history, specifically the misdeeds or bad reputation of people with that name.
Anyway, my point wasn't about the utility or necessity of men changing their names, but of the indoctrinated social norm that exists. Women have a choice, which is good. However, when everyone is freely able to choose without impediment, then women will be empowered even more (men too).
Having to explain or justify such a choice makes the choice less free, and a bit of an imposition. Currently, women can follow tradition or not follow tradition. Accepting or rejecting in the face of a social norm is not really a free choice. If a man changes his last name, he will forever have to be explaining "why" to justify his choice in the face of suspicion, doubt, and maybe even ridicule.