In the company where I worked before, the team of specialists which handled customer dissatisfaction issues often came up with seemingly brilliant solutions which would initially appear to be key breakthroughs but would later turn out to be no more brilliant than those which had been tried and abandoned before.
Along those lines, let's suppose, someone is working on a big scientific discovery or breakthrough, it's got big hype and everything, but once it is made known to public and its applications are discussed, people notice nothing useful about it and dismiss it as nonconstructive or nonfunctional.
I am interested in knowing if there is a word or phrase to describe the idea.
(Edits made to rephrase some sentences)