No, I don't see any functional difference between the explanatory text for the argument and the explanatory text for the program. They could both accurately be called "help" or "description," but for some reason the original author did not want to choose. (I agree the dictionary definition of the words are different, but in this context there is no functional difference.)

Also, your first sentence explains why I don't do what you suggest in your second sentence :-) Some people may not agree with my reasoning (which is obviously their right), not worth the trouble to figure out how to submit a patch and then risk having it rejected.