A question very pertinent yet so much debated that it may not be worth my while to write much here. Here is one and another. There are pros and cons. There is individualism and there is collectivism. Evolutionary biology suggests one way while sense of fairness suggests something else. For some it’s deal breaker, for others it’s mere practice to be followed at will. He might think that her question itself insults relationship. She might think that his expectation does the same. There is convenience of accepted norm or there is pride of carving out your own path. For some, it’s simply matter of showing love, while for others showing love itself like this is questionable.
Questions like this while getting debated in public forum don’t yield much result since they are for couple to decide between themselves. However, such debate can have effect of influencing social change. What do I think personally?
I will want my wife to want to change her last name to mine though I don't necessarily want her to change her last name to mine. Love is collection of such unstated wishes which are inherently contradictory.