There are too many things that can effect the height of a child. Even if the parents are tall, they can still have short children. For example, my grandmother is 5 foot tall, and yet she has 2 brothers who are over 6 feet.
So there is no sure way to predict how tall children will be...a recessive gene could come out and a very tall child could be the result of a short couple's union. The only thing that you could say is that there is more of a likelihood that taller parents will have taller children, because it seems that they have more dominance in the tall genes. However, if one of the tall parents had come from short parents, they would be recessive themselves for being short, but would carry a dominant gene for being short onto their children.
There is no reason why tall people should not have babies any more than anyone else.