I first heard "Imagine" on a German radio station in 1972. I immediately thought it was inspired by Marx's Communist Manifesto. However, I didn't know who sang it because the DJ didn't back announce what he was playing, so I assumed it was some obscure American or British Communist balladeer. They didn't play it on the Armed Forces Network's AM station in Kaiserslautern, where I followed the rock charts, so it was several months before I knew who sang it.
Yep most people who like it have never read the words real close. It is Marx/Communist spewage.