It's not really minor, considering the premise of the article is "[this] suggests our ancient ancestors dined primarily on tiger nuts." I've already seen this article posted in an attempt to debunk the paleo diet, but this species' diet really has no more bearing on what we should/shouldn't eat than, say, a modern chimpanzee. Which isn't to say any of the widely varied forms of paleo diet are or are not close to what direct ancestors ate or are or are not a good diet for modern humans, just that this doesn't suggest one way or another.
Nobody thought of it before? A lot of research comes from a single "wait a minute, why does this happen?" Most people thought it was related to temperature, then most people thought temperature was an old wives' tale but had no idea the reason.
Last I knew which was a couple years ago they were already machining a pair of spheres, and were going to make the standard based on the number of atoms in said spheres.