It's just this generations equivalent of rock and roll. It's just so silly cause the reasons for hating it have to get ever more complex and nonsensical. Before it was temptation+satan, now it's temptation+fake_brain_science_woo. Ironically societies collapse when the current structure become unsustainable and the younger generation can't adapt quickly enough.
In an information dense world with very little shared context you need a short attention span to get anything done. Breadth over depth. Previous generations, on the whole, lack the shared cultural empathy to thrive in the modern world. At best they could conquer their enemies and force them to consume their cultural artifacts. The new generation lives in tens of thousands of disparate cultural contexts. In many ways the "deep" knowledge is handled for you by the algorithm, in the way that a village elder would handle it for you in the past. The amount of deep though necessary goes down when an AI can translate every language, dialect and lingo even drawing. This makes gatekeeping much harder which lets be honest, is the main reason people "think deeply" in the first place.