Well, most prophecies are self-fulfilling. Sometimes it happens deliberately -- nowadays, for example, Chabad and other Hasidic groups are obsessed with "bringing the Messiah" and exert a lot of (also political) influence to enact it according to how they imagine such "coming of Messiah" should look like -- and sometimes it happens unconsciously. So there's that.

That video sums it up pretty nicely. I must argue, however, that that so-called utopia is possible. It only cannot be institutionalized and dictated from the top. It really has to spread through society like leaven through flour and grow from a tiny mustard seed into a big tree that houses many creatures. In other words, only (so-called) enlightened individuals can create, group themselves into, an enlightened society, i.e. "heaven on Earth."