Re: Optical metamaterials are just rescaled RF antenna theory
Superficially you may have a point; but no-one in RF antenna theory ever bothered to use such ideas to implement specific concepts and applications as the metamaterials research community has.
Dolin, in 1961, proposed a scheme to implement a radial invisibility cloak; but somehow all the RF antenna theorists in the world never proposed a scheme to implement it. Veselago, in 1968, noted some weird properties for materials with simultaneous negative permittivity and permeability, but somehow the RF antenna community failed to explore the implications. And looking at the scale of the early split-ring resonator metamaterial elements from the 2000's, it is more than plausible that they could have, had they wanted to.
Instead, it took John Pendry and co-workers' rediscovery to get the ball rolling and actually start trying to get interesting things done, and devices (from the exotic to the less so) implemented using what we now call "metamaterial" ideas.
You might also, for example, note that all the "entanglement" language that quantum theory guys use is just a new badge pasted over the old "superposition" label. But the change of name came along with a mindset change where the effect was now considered an exploitable resource, rather than a passive property. That change in mindset, which is on the face of it even more ephemeral than the case for RF-to-metamaterials, is an absolutely key feature of modern thought in quantum mechanics.
Sometimes it's not the building on past work that counts, it's the complete reimagining of the potential for use that does. And sometimes it is the reimagining that counts, not the past work that is (now) easily replicated.