I would frame it as it being important that you both love the name you choose for your child. He had no objections to the name you chose, so it's not the same situation as this. I assume if you'd wanted to name your child Pigpen because you loved the Charlie Brown character, he'd have objected to that. Obviously Madoka is not a derogatory name, but it is a name you dislike and both parents should have veto power because it's not great for the child to be named something that has negative feelings attached for one parent.