I can understand where you are coming from and it is a great thing to have the type of family values that you have. I wish I were that lucky. There could be a lot of unresolved issues he has with his father that he is not ready to deal with. I have a lot of issues with my father who physically and verbally abused me most of my life. I do not want to be anywhere around him, holidays or regular days. So I can understand where your boyfriend is coming from.

The best thing to do is talk to him about family values and having children. Let him know how you feel and your concerns. My brother has raised his kids the complete opposite my father raised us. That may be the case with your boyfriend. You never know unless you talk to him about it
If he refuses to talk about it then keep on asking him. Just pick a different day. If he continues to refuse, then I would start to think about your future and reality.