This article's title partly honors the new Star Wars movie that just came out, but it does deal with a topic I consider to be very important to voluntaryism and anarchism.
By "falling to the dark side" in this sense, I mean considering yourself to be a voluntaryist for a while only to change your mind later because of some problem or scenario you have trouble contemplating in a society without government. Here are a few of the reasons I've heard from some people as to why they no longer support voluntaryism/anarchy, and I want to address these points one by one to try to help people gain a fuller understanding of the principles behind voluntaryism, along with why governments are and always will be illegitimate regardless of any concerns or problems that may and will arise in a stateless society. These are also the main reasons many don't reconsider what they believe they know about the concept of government to begin with.
I will try to make the counterarguments as brief as possible, because what I want is for the main key points to sink in, as I believe it is more effective in getting people to understand how these concepts relate to anarchy/voluntaryism and why governments are illegitimate.
1: The state has to exist so that it has a monopoly on the use of force to be powerful enough to take down organized crime and gangs.
There is no institution more dangerous than one with a monopoly on the use of force, as this power can easily be abused for the sake of gaining more power and control, and usually is. The age old question of "Who watches the watchers?" comes to mind.
2: It's just not possible to get rid of government in society because of human nature; some will always want power.
Yes, some will always want power, and they can only obtain it if people believe the idea of political authority is legitimate, and that some should have this power. Once people realize that there is no such thing as "authority", since there is no reason to obey flawed people called politicians just because they write stuff down and call it "law", it will become much harder for power-hungry sociopaths to control others.
3: Humans are social and need to organize, which is mostly achieved through the state.
Organization can be and is achieved without the state all the time. All it is is people working together towards something. No one needs to be forced by the government to do so, and it's easy to argue that most don't like to be bossed around.
4: Governments are legitimate because the people have consented to be governed by them.
It is impossible to know every action politicians will take while in office, which makes it impossible to consent to something that you don't know will or will not happen. I wrote a rather short article about the idea of "The Social Contract/Consent Of The Governed" here: https://steemit.com/anarchy/@censoredrefugee/the-absurdity-of-the-consent-of-the-governed
5: Without the rule of law, anyone has the right to do anything they want.
The principles of self-ownership and non-aggression will always apply, regardless of what random people called "politicians" write down and call "law". No one has the right to attack another because it causes unjust harm, not because it might be against the law. In addition, writing words down and calling it "law" doesn't give anyone the right to attack another either, meaning morality and the principles of non-aggression and self-ownership are above the law, making the law irrelevant.
6: It's more effective to be politically active to minimize the size of the government.
Voting and any other form of political action will never lead to a truly voluntary and free society, because it still implies that governments are legitimate, which is the main lie they use to forcibly control people in the first place. It also doesn't guarantee less government intrusion in the long run. Someone like Ron Paul who advocates for freedom might be elected, but that person won't be in power forever, and anyone else who likes big government can replace him at any time.
Those are main arguments that come to mind at the moment, but if you believe I missed something that I should have covered, let me know in the comments!
Also, I used this picture in another one of my articles, but it illustrates the idea of politics so well that I love sharing it:
All it takes is walking off the plantation and realizing you own yourself and that no one has the right to force you against your will, including those in government.