I have enough inheritable minor health problems that have stumped a few great medical minds and have been no joy at all. The chance that a kid might inherit any of them makes having one just unthinkable to me. Yes it is a judgement call.
My wife has no desire to have children. Being uncle and aunt are OK with us are OK.
My children (adults now) have wonderful aunts and uncles with whom they enjoy socializing. IMO, the point of having children is less about passing on genetics and more about teaching and inspiring - which you can definitely do as an uncle.