There is no bad news or good-news because sometimes what seems good news later turn out to be bad news and what seems bad at the beginning later turned out to be good news .It all depends on the situation and what is happening.
You are saying something that I cant understand even when I tried to understand for three to four times. You are saying that sometimes the news which seems to be good is bad in reality and vice versa. Can you illustrate this thing by giving an example from your daily life to us? For me a good news is a good news because wouldnt change out in a bad news at any cost.
A good news can be a bad news but not for same person occasionally. This might be good for some and might be bad for someone other at some time. Like if we listen some news about bitcoins that they are just started dropping off the price so this can be of good news for those who want to buy bitcoins and they were waiting for low prices and it can be bad for those who were willing to sell at high.