Let's be clear. There is a principle behind minarchy, but it's probably flawed. The principle is as follows:
There are things that require monopoly use of force, but that because the use of force tends to be abused, the organization trusted with that force should be kept to the absolute minimum.
That's the principle. We can all poke holes in it. I resisted even commenting on it because I figured I'd be attacked as if defending it--as I have been on other topics by one individual.
The next question is obvious. What things require a monopoly of force, and why? Likely answers follow:
National Defense: Everyone else has one, and they all go on offense eventually (see first principles.) If we leave this to the market, no one will pay, or they'll become gangs we can't control.
Police Force: If we leave it to the market, no one will pay, or security forces will become gangs we can't control.
Courts: Only government can have an unbiased and detached justice system. If we leave it to the market the highest bidder will get the justice.
Borders: Someone has to stand at the borders and keep the bad people out. If we leave it to the market no one will pay, and bad people will destroy civilization.
By now you see the general theme. I will not defend the details, but I understand peoples' gravitation to the minarchistic principle. It apparently has a major flaw. Power has to be given to someone to do these things that we won't trust the market to do. That power will be abused, no matter how small the institution of government originates. The same evil used as an excuse for a need for government is the evil that will corrupt those in government. It will grow and become tyrannical, because it attracts tyrants.
I find it easier to defend the idea of less government than no government, because people rarely believe that anarchy is attainable or sustainable. What's more, they think anarchists are a bunch of bomb-throwers. (QED, in their minds.) This is why I bother to campaign for minarchy, and not anarchy. Frankly, I'd rather have no government, but I'm a realist.