simplism

[ sim-pliz-uh m ]
/ ˈsɪm plɪz əm /

noun

exaggerated simplicity, as in concentrating on a single aspect or factor of a problem or situation while disregarding others; oversimplification: The senator is given to simplism in dealing with international issues.
an act or instance of oversimplifying: to offer simplisms instead of analyses.

Origin of simplism

First recorded in 1880–85; simple + -ism