Yes it's normal for some people to not grow armpit hair.
Most people do have armpit hair but some people do not grow armpit hair and that is normal.
Our bodies are all different and if you have no armpit hair and someone else in your family does then that is normal.
Having no armpit hair is not because of any medical condition but it's just the genes that you inherit so if you have no armpit hair then there's nothing to worry about.
I hate my armpit hair and wish it would go away but it doesn't and likely will never go away.
I also hate my facial hair which is my beard and I shave the beard every time the beard starts to grow as it gets in the way of eating and it just feels uncomfortable.