Here's why:
* Stereotypes are simplified and often inaccurate generalizations about a group of people. They focus on shared characteristics and ignore individual differences.
* Individualistic implies uniqueness, individuality, and a departure from general patterns.
Therefore, a character who is stereotyped would be the opposite of individualistic.
Here are some other adjectives that DO describe a stereotyped character:
* Predictable
* Clichéd
* Generic
* Typical
* One-dimensional