Also, completely unrelatedly, if you saw some armchair internet rando claim they'd debunked a major and long-standing business strategy of market sector leader, how seriously would you take them?
Business is subject to fads and stupidies, we have proof that open officez are a net negative, yet businesses continue. We have proof that getting people to change passwords every month is bad for security, but its still policy in many places. We have proof that using basalt or stainless rebar in RCC is more cost effective in the long run, but bs still continues.
For urban life multiple doesn't make sense. For professional/rural it really does.
At a certain point in my life, one where I sought fewer material comforts (and had less media exposure), I used to claim that advertising won't convince me to buy anything but it may convince me not to. There is a very fine line between persuasion and overstepping ethical boundaries.
And it kind of makes sense if you think about it... really, what are the consequences of seeing these silly over-recommendations? Did you stop buying from Amazon? I bet the vast majority of people shrug or laugh, but don’t change habits.
Also, big one-time purchases tend to be rare, so optimizing a recommendation system around those is probably suboptimal compared to optimizing it around frequent consumable purchases.
Or you tell all your friends about it and end up having a conversation about guitars/dishwashers or whatever.
It may not be intentional on their part, but spin off conversations can be a nice by-product for them. Feels like it helps it stick in the mind, a bit like writing a witty TV ad.