I agree, in certain times moving the goalposts can lead to a mess depending on the business or the situation.
Should someone get a speeding ticket if they are going 56 mph in a 55 mph zone?
In business, I certainly understand. If you are a salesperson, and your goal is to sell 100 items, but you only sold 99, then you had a decent month, but you did Not meet your goal. “Close” would not get you the bonus money that month.
Here, we are merely talking about the weather and the message that needs sent in regard to perception of the forecast by the general public. I think that most people would rather be Advised or Warned if we are very “close” to the criteria of extreme heat, cold, snow or severe thunderstorm.
If people see or hear “Advisory” or “Warning”, then they can make better decisions to protect their life or property.