Randy N,
Using iphoto 5 I would just trash the whole originals folder and the 'revert to original' option would just grey out without any library failures or other issues. I always made sure iphoto was closed when I did it, and I did it lots of times.
I can explain why this used to work, but now will not. The internal structure of the iPhoto Library folder changed significantly in version 6. Version 7 retains the new structure, with the addition that the folder is now a Unix style pagkage file.
In v5 files were saved into a structure based on the photo date: YYYY/MM/DD. When you edited a photo the original file was
then placed inside YYYY/MM/DD/Originals, while the edited version took the place of the original inside the YYYY/MM/DD folder. See
lori_diloreto's illustration for a helpful diagram of the folder structure. With that structure, it was easy to go into the library folder to select photos for uploading or other use outside of iPhoto, because the edited files were mixed in with the unedited files. It also allowed you to delete your Originals, because in doing so you didn't lose any unedited original files. However, the old file structure did make recovering a damaged library much more complex. It also didn't work very well. I noticed that if I changed a photo's date it was moved into a new folder accordingly, but that the old folder remained in place, even if it was empty.
The new folder structure in v6 first files everything based on whether it is an original, edit, or thumbnail - Originals, Modified, and Data folders respectively. Inside each of those folders it is subdivided by Year/Roll Name. See
lori's iPhoto 6 diagram. This structure is much more common to better digital asset management programs. iPhoto '08 uses the same structure, with the exception that you must Control-click the Library package in order to access it. Recovering a damaged library is much more simple, because the photos are filed neatly based on their Film Rolls. This library runs much more efficiently, improving the speed of the application and allowing it to handle much larger libraries. More difficult now is sneaking into the library folder to grab files for uploading, because you have to know whether to get the original or look for an edited version. *It also means that if you delete the Originals folder you will lose every photo that you did not edit* (or that wasn't auto-rotated). Changes you make directly inside the iPhoto library folder are guaranteed to cause damage to your library. Sometimes the damage is smaller or takes longer to detect - sometimes it is immediately catastrophic.
The reason that the new version of iPhoto hides the library folder structure is that users of v6 kept damaging their libraries by tampering inside it. It has always been true that users were not supposed to access files directly inside the iPhoto Library folder, but with v5 and earlier it was easier to get away with it.
I hope this helps you understand the changes, and also why TD and Larry seemed to be "scathing." They just want to be as clear as possible, because we have seen so many users ruin their databases and have to start over with a fresh library. (The photos are safe, but the albums, titles, and other organizational efforts were lost.)
Regards.