That's fair BUT do you see how this is a decision that a) won't always have a clear line of demarcation and b) reflects an internal mental model of news that likely isn't universal?
For example: let's say someone reads a news article that titled "Trump Won't Rule out Military Intervention in Greenland" (god help us, a real story). Maybe you get all the "what" you need from the headline. I would argue though that omitting contextual information about "Why does he want Greenland?" is irresponsible and bad journalism. Many others might argue that in a duty to inform readers, they should collect statements from people who understand international relations to discuss implications of such a stance.
Another example: insurance rates are rising for coastal properties in Florida. That's the "what", but there is no honest, legitimate exploration of the topic if the journalist doesn't explore "why", because the "why" of this story if also a "what" of the many contributing factors. Since that "what" will necessarily include climate-related topics, it is now considered "political" by many. And in this instance, exploring "what effect" this is likely to have on homeowners, renters, and businesses seems a core element of the phenomenon.