What if your last name is something like, say, Podrats, and the wife-to-be's name is Jones.
Suffer the poor children.
Yeah, there are several legitimate reasons a man might want to take his wife's name. For example his last name could be that of his stepfather, to whom he is not particularly close. Or she feels more strongly about keeping hers...
Good on the OP and his fiancee/wife for making the choice that's best for their circumstances, regardless of the inevitable negative commentary it garners. (Exhibit A.)