In defense of utopias plausibility (really realistically defined as getting much better), their entire modus operendi is going from "obscure parlor trick with marginal impact" to "world changing" and seeming to come from nowhere to anybody who wasn't attuned to a previously obscure field. The green revolution averted "inevitable starvation and widespread war from lack of resources". Revolutionary changes basically like to ambush people by definition.

Public sentiment is also a pretty damn unreliable predictor of improvements.