Why was it so special that John the baptist was not called Zechariah?

After reading 2 chronicles 1-8 (many, many names) I was surprised that noone had the same name as their father, or grand father. I remembered the story of Zechariah not being able to talk until he told the name of his son, John. The people who heard the name were surprised because no one in the family had the name John. Why was this so surprising, because in the lists of names in the bible, I do not find people having the same name as their father?