Some topics are simpler than others. For example, a lot of stories on "science" tend to focus on people instead. They tell the narrative of the research team, and their success, and usually pick out a single individual to tell a human story about. Often this takes a moralistic or political angle. "A [politically fashionable identity group member] has [destroyed boundaries / revolutionized topic / other post-modern language]." This is not necessarily a bad story to tell, but it's clearly about people and groups of people, rather than a story about science.

By contrast, if journalists were solely focusing on the science, the article would simply be a reprint (or summary) of a research paper. Now, to be fair, some news outlets do a very nice job of this, while others turn everything into a human story, or at least, focus on a part of the story the journalist can understand.

I think this is partially due to the limitations being described. The journalist likely can't understand the science in a meaningful way, but can understand the people, and how they talk about their research, and how the public perceives that. Helpfully, this will also likely be the story that will appeal to more readers. And so, the incentives are aligned in a few directions against the "better" (read: more precise, and requiring more expertise) story.