I read an article over 20 years ago that held forth that if we really were looking for ET, we needed to be looking at laser light in the visible range since that's what any sensible civilization would do. Hell, 35 years ago Niven and Pournelle put that idea forth in "The Mote in God's Eye."

I read an article 10 years ago that said "well duh lasers are passe we should be really looking for pulsed microwave emissions."

It might have been Seth Shostak who pointed out that SETI is one of the most "fashionable" sciences, in that it's driven by whatever the prevailing fashion is at the time. Percival Lowell, for example, was looking for canals on mars not just because he didn't bother to look up the Italian word "canali" but also because big damn canals were the engineering marvel of his era. So yeah. I'm right there with ya when you point out that this article is about looking for space LEDs.

At the same time, it's a "free" search. You don't need extra gear and you can piggyback on existing or proposed telescope missions. There are two parts to observation: "what are we looking at" and "what are we looking for." The "at" is booking time, but the "for" means "which instrument package do we strap on" at worst.

I read an interesting article in Scientific American a couple years ago about searching for extraterrestrial flora. The author pointed out that with next generation scopes we could theoretically be able to detect life on other planets simply by looking for that star's equivalent of "chlorophyll green." The trick, according to the article, was in knowing what color that would be depending on the star.

It's all spectra, after all. It just depends on what you do with it.