I agree that taking a man's name is a non-feminist act.
I really struggled with this upon marriage. I knew that as a feminist I should retain my own name and didn't change it for a couple of years. I had a surname I didn't particularly like, from a father who was not around and who had paid no child support.
My ex manipulated a situation whereby it would have cost quite a bit of money if I didn't change my name so I went ahead and did it.
I then had years of career progression in my new name, a child, to whom I gave my married name, and then a divorce.
I've kept this name, which has become my name, for professional reasons and to have the same name as my child which I do appreciate.
My compromise with my feminist principles is that I intend to take a new name and change by deed poll when DD is 18.
I had considered changing it to my mother's family name but I have a male cousin who has started addressing me with that name - he also tried to get my mother to revert back to that name. I think he believes himself to be head of the family and custodian of the name. I was very angry when he sent me a letter addressing me with this name as it's a name I have never borne. So it does feel that my mother's name is also part of this patriarchal tradition to which I do not wish to conform.
So whilst I think it's a non feminist act to assume a man's name, keeping it is sometimes just the pragmatic thing to do.
Names appear hugely important to men; you see this particularly in their insistence that children take their names. I know several women who retained their names on marriage but the children have the fathers' names. There was a thread not too long ago where a man was trying to convince his pregnant partner to have an abortion and said if she went ahead with the pregnancy he wanted nothing to do with the child- but was insisting it should have his name.