If you want to argue for a guideline, and I believe Damian Conway says this in his book as well, you need to discuss the benefits over its drawbacks. [...] Simply citing verse and chapter of a book that has many flaws does not help your argument.

If a monk has no original thought beyond what's written in a book somewhere, I think I'd prefer a reference over a paste or paraphrase.

Update: Upon further reflection, I guess I prefer the reference mainly in the case where I've already read the book. Unfortunately, the poster can't always know which books I've read.