I still think it would be bad to underestimate the symbolic (now and in the future) importance of the name. It is a tie to the Father and if he gives this up he is lessining that tie. It is important! It is worth putting your foot down!
As an aside... Babies really should take the mothers name. Afterall....you know who your mother is. She tells you who the father is . But agree with the choir here. Keep the fathers name. Lots of kids have different names then their mothers. Lots of married folk have different names. It's part of who the kid is. Can't see justification to change it.
