I would argue that Tools like turnitin et al and their use of a "plagiarism score" are at least partially to blame. Teachers already in high-school seem to often tell students to self check and that "a score above 20" (arbitrary number) will result in a fail, as if some percentage of plagiarism is ok.

I was shocked when I took over a thesis course and students were asking what was the acceptable score. They also told me that students had failed previously due to a too high score because turnitin picked up the reference list as plagiarised. Now this is clearly the fault of teachers, but the increasing demands on them, plus the turnitin advertising to easy the burden by making this score is also partly to blame IMO.