The problem with that is that it's possible for the docs to be clear, seem complete, and describe friendly syntax... and be wrong

Which of course a doc review would not highlight. But normal testing and use would.
I'm not advocating POD review as a replacement for functional testing, but as a way to get more people involved in distribution QA in a way that is easier and more accessible than performing full blown testing, and getting a 'first pass' done on a wider range of modules.
After all, full testing on every module on CPAN is well nigh impossible, but if we could get a POD review on a wider range, that would be better than nothing.