1: "Watermelon has too much water content for creamy smoothies."

2: "It may dilute the flavor of other ingredients in your smoothie."

3: "Watermelon's natural sweetness can overpower other flavors."

4: "The texture can be too watery for a satisfying smoothie."

5: "It may not blend well with other fruits or veggies."

6: "Watermelon smoothies can lack protein and nutrients."

7: "Using watermelon may increase the sugar content of your smoothie."

8: "Some people may be allergic to watermelon in smoothies."

9: "Consider other fruits for a more balanced and flavorful smoothie."