It wasn't. It perhaps should've been, but instead, it was just "legitimate marketing practice".
This is another facet of a larger phenomenon, that I just commented on in another thread[0] - there's a lot of harmful activity that's considered legitimate, thus invisible to our legal and cultural immune systems, yet no less harmful than the slightly less legitimate scams.
Your linked post seems to be a polemic, not a legal analysis. Many advertisements are subject to successful (expensive) class-action lawsuits based on some fraud or truth-in-marketing claim. Also, this isn’t an advertisement, it’s a communication which takes place under an implied contract.
This is another facet of a larger phenomenon, that I just commented on in another thread[0] - there's a lot of harmful activity that's considered legitimate, thus invisible to our legal and cultural immune systems, yet no less harmful than the slightly less legitimate scams.
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[0] - https://news.ycombinator.com/item?id=42401894