Is Plagiarism a Bad Thing in K-12?

The more I'm exposed to kids who struggle with school work and homework the more I believe we do these students more of a disservice by getting hung-up on plagiarism.

It seems to me that students who research and organize well written content to add to their assignments are forced to learn how to undo what's well-written "to put it in their own words" regardless of the fact that this is often a bad rewording of the original.

Now I am not advocating theft of intellectual property but merely a fair use of existing research data in pastiche form by young students. It seems to me by learning and organizing well-written good ideas they are doing more to learn proper form than by convoluting the stuff.