As far as I know utopia and dystopia are like polar opposites. I have never heard the take before that the concept of utopia includes that it´s rotten on the inside and only looks perfect. Where did you get that idea from?

A utopia (/juːˈtoʊpiə/ yoo-TOH-pee-ə) typically describes an imaginary community or society that possesses highly desirable or near-perfect qualities for its members.

and

The opposite of a utopia is a dystopia.

source: https://en.wikipedia.org/wiki/Utopia