Some insights by J. Shaftoe.  Via JPFO.
Think about it this way. If you worked at the post office, and someone said “We don't need mail anymore. We've got email now. It's faster, cheaper, and easier.” How would you feel? How would you respond to someone who told you that they can do your job better than you can, and that they don't need you anymore?

Now imagine that instead of delivering mail, you deliver security. Or, at least, you think you do. And now someone is telling you that they don't need your elaborate machinery of justice, because they have the right and the ability to deal justly with their attackers themselves. Your entire career, which you pursued at great expense, has been declared second-rate compared to three pounds of forged steel and springs.

Makes you a little afraid, doesn't it?
Read the whole thing, of course.  I've held this belief for many years.  There are people like Shaftoe describes, then there are those who do it for power, not just to protect their miserable livelihoods.

And what about those who are of good conscience but are simply misguided?  They don't exist.  Never have.  If they were truly of good conscience they would see the truth and cease to willfully spread lies to get their way.