Replying to myself with a few clarifications because previewing my post three times is clearly not enough.
0. I forgot a sentence somehow. After the second paragraph, imagine I said "Conversely, the new method is like the industrial bakery -- there's a constant stream of nanowires being manufactured at high speed, and you don't have to wait for an oven to cool down, remove your wafers full of nanowires, then wait for the oven to heat all the way back up before starting another batch.
1. For some reason I decided that the nanowires reported here were metallic -- they are actually III-V semiconductors. Most of what I wrote above still applies, though to get the same plasmonic properties of metallic nanostructures you'd have to dope the nanowires pretty heavily (and even then you'd just wish you were using a metal). Semiconducting nanowires also have interesting optical properties, so if you're not interested in the details you can get away with just doing s/metallic/semiconducting/ on my post.
In more detail, though both metallic and semiconducting nanowires have abnormal optical properties, the mechanisms are different - semiconducting nanowires have very sharp jumps in their absorption spectra due to quantum mechanical confinement (in short: electrons in the structure can only take on certain energy values, so only photons of a particular energy can be absorbed. That's not entirely true, of course, because the electrons in nanowires aren't actually confined in every direction so the absorption features get spread out), whereas metallic nanorods have weird absorption, reflection, and transmission due to the coupling of the electric fields of incident photons to the electrons on the surface of the metal. You can still get plasmonic effects from semiconductors, but they're generally much weaker as the free electron concentration is just that much lower.