In the parable of the ten minas, why does the king kill his enemies?

Jesus is talking about the time when Jesus is back to the world as King... the second coming. The time of grace is over by then. That time, whoever is willfully against his kingdom will be punished because they know that Jesus is God and still do not want to acknowledge him. Jesus is talking about the guardians of faith who rejected Jesus. To prove the point, let's see how another event unfolded. Jesus healed a blind person who was blind from birth. He did not have eyes at all. Jesus made clay out of spit and spread it over his eyes. It resembled the act of creation of the first human, where God made Adam from earth. Elders in their heart... they knew this was God for sure. But they did not want to concede and lose the privileges that they were enjoying. Remember, Jesus did not allow them to do business in the temple. At the end, Jesus said this remarkable sentence: John 9:41 -- Jesus said, “If you were blind, you would not be guilty of sin; but now that you claim you can see, your guilt remains. These guys did know Jesus was God, but did not want to give up their positions. By doing this, they willfully sinned against their conscience. A Muslim, a Hindu or an atheist may not be judged as severely as those Pharisees because they may not be working against their conscience. James 4:17 -- If anyone, then, knows the good they ought to do and doesn’t do it, it is sin for them. How much the sin will be, if you know that Jesus is son of God and you don't accept him.

It seems pretty clearly to be referring to the day of judgement in the form of a parable:

1. The disobedient servant is a Christian who was false (in name only, as we would say): he loses his reward since lip service is meaningless;
2. The others are plainly the enemies of God; not so much those who didn't believe in this life, but those who want to rule themselves outside of him, the demons primarily, but also heretics, apostates and those who reject him at the end.

We cannot interpret this parable as speaking of open violence against non-Jews because of the simple fact that nobody there interepreted it that way; no violence followed the command then or afterwards. It is clearly understood - and maybe our translation makes it difficult - that these words were part of the story and referring to the final inception of the Kingdom on the day of Judgment.

1. This is a parable, so the fact that "a man of noble birth" is third person is rather irrelevant. It's pretty obvious he's symbolizing someone, probably Jesus.

2. Context. Verse 11 reads:

   As they heard these things, he proceeded to tell a parable, because he was near to Jerusalem, and because they supposed that the kingdom of God was to appear immediately.

   I think it's easy to gather from this that:

   1. The parable was being told to show that the kingdom of God would not appear immediately
   2. This parable was about the kingdom of God.

3. With this in mind, and knowing that the kingdom of God in Jesus's parables often refers to the day of judgement or the end times, we can make a couple of assumptions:

   1. Jesus is the nobleman. He often is, and he goes to "receive for himself a kingdom," something especially reformed scholars says Jesus is doing (receiving a kingdom from his Father).
   2. The followers of Christ are the ten servants.
   3. Those servants that pleased the nobleman with the abundance of minas are those saved by Christ who have lived out their lives "according to their calling." They have confirmed their faith through works, as James says.
   4. The one who fails to multiply the mina is not one of Christ's followers, but a tag-along; like the seed sown in the rocks.

   5. Point 4 is made more obvious in verse 26, which reads:

      I tell you that to everyone who has, more will be given, but from the one who has not, even what he has will be taken away.

      Those who multiplied their minas "had" - they had Christ, truly. Alternatively you could say they truly "had" their mina, because then to them more was given. Either way, they had something (salvation) and to them more (eternal life) was given. To the man who hid the mina, he had not (no salvation) and so even everything else he had (life) was taken away (cast into hell).

4. As to verse 27, notice that the nobleman is still talking within the parable; Jesus is not talking directly. So we're still within the parable, which is happening later (point 2.1). The nobleman (Jesus) will, on the last day, cast into Hell those who did not want him to rule over him, just as he "took away" from the man who failed to multiply his mina. (There might be a difference between what happens to these two groups, maybe, maybe not. Regardless, those rebelled against Christ are being punished).

5. So no, Christ isn't "ordering open carnage against those who didn't follow the Abrahamic faith", he's sounding a warning that on the last day those who rebelled against him will perish.

^{N.B This answer, like many, is quite speculative. I've tried to stick to what I've heard preached and the typical Evangelical interpretation of the passage. The beauty of the votes is that they (should, anyways) show if I'm well representing that position.}