How did this get a negative connotation?
This is the idea that a perfect society can somehow be created where there is no suffering, poverty, conflict, etc. This society will need to be engineered in some way, and can usually only exist through cooperative effort.
This is antithetical to many groups in both political and religious contexts, and, as such, the word is often used pejoratively to imply that someone’s beliefs or policies are frivolous, silly, or sinister.
Many political groups equate utopianism with increased government control, and the submission of the individual to community. Right wing groups in the United States sometimes refer to Left wing social policies as “utopian.” They believe that utopia cannot be achieved due to the fundamental nature of man, and the simple fact that different people hold different values and desire different things.
Many religious groups – particularly evangelical Christian groups – oppose utopianism (or what which they characterize as such) on the grounds that a perfect society cannot be achieved outside of God due to Man’s inherent sinfulness. Striving for “heaven on Earth” is heretical in the sense that true perfection can only be achieved through union with God, and any attempt otherwise is an attempt to replace God with Earthly substitutes.
The word “utopia” was invented in 1516 by Sir Thomas More. It’s a made-up word that he formed by combining the Greek words for “no place.”
Why I Looked It Up
I can’t remember exactly, but I did have a politically conservative friend that mentioned it several times in relation Democratic policies.