Because the system is not a given in the first place. The error is made so early that it's quickly skipped over and unnoticed. Once you are in the state of understanding a system, it's already too late: the system has already won, because it convinced you of the existence of rules that don't actually exist.

How the social system is isn't a given. It's not a solid framework of hard rules like the laws of physics. It's rather amorphous, and, in large part, it's driven by what people believe it to be. We can favor the loud. We could have just as much chosen the quiet. It's a bit more complex than this but the statements aren't false. There's a path to both.

One doesn't have the capacity to look at a system and claim they understand it, because the internal system is always affected more by the larger external system, which has not been understood. Understanding it would imply to fully know all the effects. Yet people claim to understand systems all the time, and then the system is swept under by a new wave that didn't care about your understanding. Really, the system wasn't truly understood, and it's too big to be understood, which seems obvious: if we really understood these systems all that well, we'd be free to guide them where we want, and we'd make perfect predictions, and the waves wouldn't surprise us. In reality, we don't understand the system; time and time again I see people treat a system as a bastion of stability and then it falls apart.

What we're doing, really, when we say that we understand the system, is that we piggyback on what someone else has claimed to be true of the system, which tends to be heuristical. Someone who is, interestingly enough, known to be experienced in navigating the very rules they state to be true.

It's like a metagame. The metagame always seems true when you look at it, and moving away from it is very painful. People who know the metagame are often very good at it. But it's often that the metagame is a shallow assessment, that gives the fastest results with the least amount of time spent, and little else. The metagame often doesn't actually give the absolute best result, but rather the most simple to reach good enough result, especially for those for whom rediscovering is difficult and takes too much time. Little surprise that metagames are unstable, fickle, and easily disrupted. Someone who truly understands the game will beat the metagame and will often not reveal their results and keep opponents in the dark for a long, long time. The opponents are then unable to find the new metagame since they're loyal to the old one. But there was never a hard rule, never a promise that the metagame was true. The metagame never replaces true understanding.

So when someone looks at a system that has obvious bad effects, and says: "I will function within this system and its bad effects, because that's just how it is", they're doing the worst thing: feeding the system and giving it the very thing it draws its power from. The more influential a person does this, the worse, for who can oppose the political system if even the great Arnold had to stoop down to such a low level? Of course, the real answer is that Arnold probably never understood the system and just adapted the metagame that was available to him to play it safe.

In that, he did harmful things, and that is how it should be analyzed. It doesn't, ultimately, matter why he did them, because then we'd play into the rules of the system that don't exist. It is only the end effects that we can analyze. Arnold losing in a political system because he was not hostile enough is going to be impossible to prove. He could as well have been more effective if he did something unusual and did it right. But him having a negative influence, and reinforcing an already bad system, are very visible effects, and those are the ones we should look at.

Anything else is Machiavellianism and the claim that doing harmful things is OK, as long as they make YOU personally more powerful because you think you will have enough agency and forward-thinking and power to change the world for the better while obviously making it worse for the people you touch. I think we can find a more effective way to function as a society than promoting Illidans.