The alien people, most of them, look scary.
They don't look scary to races that are already used to meeting so many different other races.
Anyway, scary is as scary does.
We humans are the race that all the other races in our area "fear" because we are dangerous.
If we were allowed to travel yet, we would do out there what we do here.
Our governments are responsible for all of that.
Not you and me.
It's normal to react in fear, and protect yourself, to defend yourself until you realize you're not in danger.
That is not the same as launching war.
Details
Our fear is natural and instinctual, but can easily be overcome, because it's of the unknown.
If you get to know what you're afraid of, it's not so scary anymore.
The disinformation cements the fear.
Ever go to the mall, and be in a crowd?
And you look up and there is a disfigured man, from war or an accident?
The sensation that flies through your body is natural.
But if you see his own family with him, they have no such fear.
And if he was your neighbor, and you just talked with him for a few moments, you would see past that too.
Conclusions
Well, there are things to fear rightfully so.
There are bad people in our world, whether by deformity or by desperation, we do need our instincts still here.
There were some alien races who were taking advantage of some humans too, but not anymore.
It happened for an extended period of time, I don't know how long.
It ended completely in April of 2000.
It was stopped by the organization of visiting races.