simplicist
/ˌsɪmplɪˈsɪst/Definitions
1. noun
A person who believes that something can be explained or understood by breaking it down into its simple parts
“The professor was accused of being a simplicist for oversimplifying the complex social issues.”
2. adjective
Relating to or characterized by a tendency to oversimplify complex issues or ideas
“The journalist criticized the politician’s simplicist approach to the economic crisis.”