Simpleminded (adjective)

Lacking complexity or subtlety in thinking.

Origin:

From simple + minded.

Examples:

1. He was criticized for being simpleminded in his approach to the problem.
2. She is not simpleminded, she just lacks experience.
3. The movie was criticized for being simpleminded and not thought-provoking.
4. The simpleminded solution was to just ignore the problem.
5. The simpleminded person cannot understand the complexity of the situation.