Your last question is loaded; it assumes maximizing profit is bad. In practice high profit margins are often a reward for being first to market. Maybe those high margins are a recompense for R&D costs. Plenty of answers to rebuke your suggestion that maximizing profits is unethical. It's also a situational topic made more nuanced by the specific product, company and many other circumstances.
The article is not advocating for the "manipulation" of anyone. It's up to the reader to implement, ignore or consider. If the title and some words were rephrased it could be an article on how to spot pricing tricks; the content would mostly be the same.
But we have found that spending money on trained psychologists (or schemes developed by them) who abuse natural human tenancies to trick consumers into irrationally spending money or more money on your products is very effective at maximizing profits. But it simultaneously removes the condition that's required to make maximizing profits a good thing.
Fraud is also very profitable.
> Your last question is loaded; it assumes maximizing profit is bad.