That's easy. It's fear. Picture this:

You're an industrialist, trying to modernize a backward planet and raise up standards of living through the use of technology, for the common good. One day, some of your industrial robots are blown up by a sentient, supersonic blue hedgehog. That's scary as fuck. Now, said hedgehog has it in his head that you're a monster who's turning animals into robots and wants to take over the world and oppress it, in large part because of all the steroids, speed, colloidal silver, and other assorted shit he's been taking in massive quantities for the past decade. You decide to see if you can't reason with the guy, but for your troubles you get assaulted, and your ride gets trashed beyond recognition.

So you decide to deal with this like you would with any other pest problems: You put out some traps, like spike pits, modify a couple of your robots with .22 rifles, etc. The way you'd deal with any rodent, really. Soon enough, the hedgehog gets himself impaled, and you're done. Or so you think. Soon after, despite having quite clearly been drained of his precious bodily fluids, he's back and trashing your robots again. Maybe the other one was some sort of decoy? No matter, you're taking this into your own hands. You modify your ride, mad max style, adding a couple of guns, some spikes, missile, slowly swinging giant balls, that kind of stuff. Then you roll. You meet the hedgehog and after a brief struggle where he manages to make one or two lucky hits on spots you haven't really bothered armoring, you make him into thin gruel. This time you're sure he's done for.

How wrong you are. Soon after, he's back. You can't believe it. You try to kill him yourself once more, but this time he seems to know where to strike. He seems to know when to strike. He seems to know when you'll strike. Once you realize that, you try to change your attack patterns, but it's too late, he's done enough damage to blow up your vehicle, and you barely escape with your life. For the next few days, he follows you, destroying everything you throw at him, and it's obvious he won't stop until he gets you. You can't sleep. You watch as he destroys everything you've done to help people: one after another, chemical plants, oil refineries, amusement parks, all you've built, gets blown up by this satanic, unholy, immortal demon from the deepest pits of hell. When you do manage to take him out, he's back within hours.

Eventually, as you're trying to escape to the one place where you think you're safe, space, he defeats one of your latest creation, and for the first time, you're face to face with him. There's no steel plate protecting you. There's no vertical distance. He's there, staring at you with those empty, demonic eyes.

You run like you've never run before. You just fucking run.