The ever increasing use of the term "Neo-" since 1945 suggests that today we differ greatly from our grandparents in no longer holding fast to their Faith ---- a faith in ever-onward progress.
Today we often prefer a self-conscious circling back to older ideas (usually meaning "anything other than modernist" ideas) , rather than constantly seeking out ever newer ideas.
But because of our awareness that those older ideas have been very heavily modified by the weight of history upon them since they were first articulated, we prefer to prefix them with Neo- .