We believe it's easier to select a dropdown rather than type some "funny" data in a form. After all, it's an age check, not a 100 questions survey.
Regarding the design and other aspects, you could have asked or suggested what you think will look better for your design. We helped a lot of people customizing the design.
While this product was built for functionality, changing the look its very easy with basic skills.
We're sorry to see you've spent more time giving us a poor rating instead of helping to improve the product.