I whole heartily agree. SA used to be a great scientific read. I don’t remember when the train wreck occurred, but it might have been two decades ago. I think I dropped my long time subscription in the late 1980s.
Here's how I remember it.
Back in the '70's (from about 1970 until I left home in 1979) I had a subscription to SciAm. Sometime around 1978, they published a very strange thing. It was a sort of an advertisement, but it was an advertisement sponsored by Scientific American itself. It wasn't an advertisement for the magazine, or for anything directly related to science at all. It was an advertisement for a member of congress. It was an advertisement for a congressman: Les Aspin.
The text of the ad promoted Aspin as a great man, a fine representitive with a futuristic outlook, a man ahead of his time.
I doted on SciAm almost religiously at that time. I devoured each issue; the articles, the columns (I lived for The Amateur Scientist and Mathematical Games, although C.L. Strong passed away in 1977). When the wierd "Les Aspin" commercial appeared, I thought "what an odd thing to have in Scientific American."
From that moment forward, I watched the magazine slowly deteriorate (from my point of view). Fewer articles about hard science, about cutting-edge technology. More articles about nuclear disarmement, nuclear winter, delivering medical care to third-world countries, and the like. During the 1980s, SciAm was a champion of the "Star Wars is a dangerous fantasy of an ideological ignoramous" meme. Every MIT professor who had something to say to bash the idea got his turn at bat. By then, I no longer subscribed, but I did buy the magazine from time to time at newsstands in the Philadelphia area, where I lived. It became more and more like Omni every year.
It's a shame. I still know where I can go to read those old copies (I'll not say where), and I use them for research all the time. As I grow older, I appreciate them all the more, and miss the old Scientific American.