The leaders on the Left WANT the destruction. They believe that after all is destroyed THEY will impose Utopia. What they mean is a feudal state, with a few Elites and the rest slaves.
The poor stupid leftists who follow this are just that: stupid. Prog leaders are the most evil people the world has ever know. Prog followers (all the Dem voters and many Repub voters) are hopelessly stupid.
The NEA perpetuates this because they consistently do an end run on facts of history (among other disciplines).
Liberals think the egalitarian HS is the answer to the worlds problems...as if efforts in that direction have ever served any but the already successful and prosperous Establishment.
Add to that ... Liberals blame all problems on the US. That is the fools and the lazy man's answer to the problems facing the world.