meaning - "Why don't they help him?" Why do we use simple present here?

CONTEXT

You are walking in the street and you see an old man on the other side stumble and fall to the ground. He tries to get up but he can’t. Nobody is helping him.

You say, to no-one in particular,

Why don’t they help him?!”

• Why is the simple present acceptable here?

I am not concerned with the difference in meaning between using present simple and present continuous in this case. What I would like to understand what generalisable rule allows us to use the simple present here. We wouldn't say:

Look over there, the old man lies on the ground!

so why is it acceptable to use present simple with the question:

"Why don’t they help him?"

Please see the section on "Possible explanations". This is not a suggestion like "Why doesn’t he take an aspirin?/Why don’t you go to the doctor?" It’s something happening right now, when you’d normally use present continuous, not in the future, or regularly. Present continuous would be possible, but I think this usage would be more common.

POSSIBLE EXPLANATIONS

• I thought it’s because there is an inferred "...when/if people can see he needs help" and that the "when/if" is influencing the tense? Is this somehow related to conditional? Somehow, I feel this might be the best explanation: "Why don't they help him? If they help him, he will be all right".




• Related to "performative present"? But this is nothing like "I warn you: don’t come back here".




• Is it somehow present simple in commentary? You are viewing a scene and describing it as it happens, like a football match? But it doesn’t feel like that.




• Is it just a ‘special case’? An answer in another post suggested that the construction “why don’t you (just)…” 'can be used as a rhetorical question basically equivalent to a rather crude and exasperated-sounding imperative'. The more detailed explanation goes over my head, and somehow I feel there must be a simpler explanation.

OTHER EXAMPLES (some of these may not be the same problem)

• Why doesn’t the bus come?


• Why don’t they overthrow the government?! I don’t understand!


• Why doesn’t he accept the offer?