He's an intelligent man and an author. Yet he doesn't realize that not every item that might be in a bibliography has a ISBN, nor do all books have ISBNs. Therefore, why specific information is placed in a bibliography so the item could be found later (sometimes much later) is lost on him.
A young friend of mine needed to create a bibliography for a school project this weekend.
I had forgotten how annoying this task was. I was also pretty sure it was obsolete.
Why, exactly, does a teacher or reader need to know the city a book publisher is based in?
If your goal as a reader (or someone checking for plagiarism or quality of research) is to get to the books that the writer used, you need exactly one piece of data: the ISBN.
He is not alone. I've seen this problem with high-priced reports sold to corporations in not properly citing where information has been obtained. With them, though, the thought might be that the writer has included all that the corporate reader needs to know. That corporate reader will not need to check the references or want to look at the background materials in more depth.
As information professionals and teachers, we know what to capture about a resource so that we might find it again. Sometimes it is enough to have the URL; sometimes we know we'll need much more. Our reasoning is something that we've evidently failed to communicate to others. Looks like we need to do a better job.