I'm just telling you what Jeremiah wrote. If you disagree with him that's your business.
It's our business to judge the prophets, as true or false. It isn't just those who predict good news that comes false that are false prophets. It's also those who prophesy bad news that proves false that are to be judged as such.
When you quote Jeremiah, you're dealing with a single context. You can't make a single statement in a single context apply to all occasions, to different contexts. That's irresponsible. It's also irresponsible to say that false prophecy is okay if it's negative news. I'm sure Jeremiah wasn't saying that!
2 Peter 2:3. 3 In their greed these teachers will exploit you with fabricated stories. Their condemnation has long been hanging over them, and their destruction has not been sleeping.
Does fabricated stories apply only to good news, and not include bad news, as well? "Fabricated stories" refers to *any news that is made up!* Why you don't get that is beyond me, but yes--it's all of our business. We're called to expose the lies of Satan.
I think what you're talking about is the fact false prophets ignore the need for public repentance. They don't believe God will punish the society for their sins, and whitewashes the sins so that they will be treated with indifference to their bad deeds. This is why they tend to proclaim good news when they should be warning of bad news.
When a true prophet predicts bad news and it doesn't come to pass, it is because the people have *repented,* which is the whole purpose of the prophecy, to induce change. It is not a false prophecy, because if people return to their sins, the original prophecy will indeed take place. There is some flexibility, therefore, in how we treat Jonah's prophecy that in *40 days* judgment would fall. It was delayed, due to repentance, and then later came to pass when the people of Nineveh returned to their sins.
Here Jeremiah clearly indicates that false prophecy encompasses not just good news, but also a warning of bad news if they surrender to the Babylonians...
Jeremiah 38.4 Then the officials said to the king, “This man should be put to death. He is discouraging the soldiers who are left in this city, as well as all the people, by the things he is saying to them. This man is not seeking the good of these people but their ruin.”