No, Topgolf is not exclusively for kids, but they market their product as perfect for all ages.
Topgolf provides lessons, junior camps, and even a junior academy for children who would like to learn how to play and learn more about golf. Note that children under the age of 16 must be accompanied by an adult in order to enter. Topgolf also caters to adults, with plenty of golf, food, beverages, and music providing a lively atmosphere for a whole day of fun. Oh, and if you want to brush up on your golf skills, Topgolf offers lessons to adults too.