I don't think you can define UFOs as either bad or good because they are both and neither

 Is a Grizzly Bear bad or Good? It depends upon how you feel about Grizzly bears.

Is a Mountain Lion Good or Bad? It depends upon how you feel about Mountain lions.

Is an African Lion with a big mane bad or good? It depends upon how you feel about African Lions.

So, the same thing can be said for all human beings and all UFOs.

So, are all humans good? No. There are all sorts of people from normal people to mass murderers.

And so I say to you that UFOs can be seen mostly about how you see everyone else on earth except they are from another world or another time and another world or another time (the future perhaps) of Earth or even another timeline of earth.

So, UFOs have to be approached very gingerly because you have no idea what they are thinking or why they are here (Unless you are an intuitive like me who senses people's or animals or other beings intentions and motivations.

This has always served me well in life.