When I look at humanity I see so much diversity and potential for good, wouldn't any intelligent species also see this? It seems to me that most of today's problems stem from the oligarchic capture of power that simply benefits more from the status quo than anyone else and so they do as much as possible to change it. If aliens were to come, that would be such a paradigm shift that it could steer earth in any imaginable direction.
But maybe they operate in time scales that are just meaningless for us. If they are so advanced, they might as well be immortal, so at that point you might just not care as much... I mean, we look at ants for example and they do their whole life cycles in such a short time. I don't know. I mean we've had contact stories in human history that haven't gone very well anyway. In Childhood's end, from Arthur C. Clarke, the aliens took quite a while to make contact but one day they did simply show up.
Probably not. Agree it's disheartening, but look at human history: we are ape-brain savages, doing dumb- and bad-shit all the time. If you saw a planet doing the kind of shit we pull all the time, would you want to walk up and just say "Hi, I come in peace from an advanced civilization". It's sort of like walking into the poor/uneducated ghetto and flashing your cash, and saying, "Hi there fellow spiritual being, would you like to make my acquaintance?" Favela/slum will eat such folks alive, right? The smart thing to do is not engage us--despite how "advanced" we think we are, which likely makes it hard for us to accept they don't think we are the life of the party that they, "Oh my gosh!--just have to meet!"
ALternate hypothesis is: they are imperfect just like us, and they are simply doing covert surveillance. While they try to be constantly covert, sometimes they fail and are seen by various secret or public sensors.