Prime example: The whole idea of QKD (Quantum Key Distribution), if you listen to many talks they often motivate the talk using Shor's algorithm and the idea that a quantum computer would possibly break many classical encryption algorithms in the future (that's so far still largely a theoretical result). They then sell QKD as the solution because it's "quantum secure", but QKD is a key distribution mechanism for symmetric encryption (which can't be broken by quantum algorithms). Moreover it's really just a physical layer "sensing" solution, where you can transmit data (over a special link) and detect if someone has listened in on your transmission.
So they sell a solution to the public key encryption possibly being broken by quantum computers in the future, but their solution can not replace public key encryption, because it can only secure a link between two predetermined endpoints. It's an dishonest marketing ploy.