If science fiction captures the concerns and fears prevalent in the era in which it was written, I can only come to the conclusion that people in the mid-60's were scared shitless of children.
Think children raised by wolves are bad? Think again. Children raised by children are even scarier. At least, I assume that's how people felt in the 60's. Or at least that's what the writers felt. I can only assume that they were parents.
Frankly, if children were anything like how they were portrayed in Miri, I'd be scared of children, too. The children in Miri are not just obnoxiously disobedient, they even have a penchant for violence and murder.
The children didn't kill anyone in this episode?
Apparently, denial isn't just a riverin Egypt. You can't tell me that they learned that bonking someone on the head with an object with some heft to it (like, say, a hammer) is an efficacious means of depriving them of life just by reading it in a book. For one thing, I doubt those little savages could read. No, rest assured, they learned all that through experience.
300 years of murderous experience.
Bonk bonk on the head! Bonk bonk! Bonk bonk! The head being bonked is Kirk's
Besides the interesting views on children that must have been held by this episode's writers, Miri is notable for being the first of the "another Earth" episodes. However, this angle isn't used to its full potential and it really wouldn't make any difference to the story if it were expunged. Also of interest is the continuing evolution of the Kirk-Spock-McCoy triumvirate; Spock and McCoy go at it like an old married couple but I'm not sure if their catty exchanges really count since McCoy was going mad due to the effects of an alien plague. Spock continues to display emotion and a dry sense of humor. And Janice Rand reveals to Kirk that she's been trying to get him to check out her gams for quite some time. I bet she's embarrassed she let that slip out. I guess the take-home lesson of all this is, if you're going to contract a killer virus that makes you go mad and causes you to reveal your embarrassing secret longings, avoid hanging around people about whom you have those embarrassing secret longings.
Yeoman Rand finally gets Kirk to notice her, although not under the best of circumstances