I think the tone of the governance papers do appear to be academic as at that level of abstraction, it is not possible to enumerate all the crazy things SharePoint implementations have tried. I know that Microsoft does have a lot of hands on experience with failed/non-performing sites as they have support contracts with many customers who have installed things in an ah-hoc manner and had things work poorly down the track.
I started off as a coder wondering why all the fuss about planning and governing a SharePoint installation, but over the years I have realised that getting a SharePoint site customised and up and running is the easy part. A SharePoint installation will stay running for years in an organisation and people can create an immense amount of data during that time and it all ends up getting stored.
Deleting stuff that is not used does not seem to be as easy as creating it in the first place.
The guidance may seem to be a bit fluffy, but it is distilled from some pretty harsh lessons.