Interestingly, I also found the same blog when starting out with Lightroom. There are many ways to get images organized and I found have a file-system structure is very helpful.

First is that the filesystem structure is accessible without Lightroom to every other program. You can use it to quickly located images without having to load Lightroom and wait for it to get its catalog open. Any operating system tool to search the file-system understands folders, so you have more flexibility by just having some hierarchy.

Even though disks are getting faster, having very large folders slows the operating system down. Even Lightroom is not as fast when accessing huge folders if you are in the File System view.

Thirdly, a neat hierarchy facilitates making backups. Dividing images into branches which fit on your choice of backup medium is extremely easy, particularly when you consider that Lightroom is totally non-destructive. For example, to do backups on Blu-Ray disks, I load folders with at most 24GB and back up completed ones on write-once media and the incomplete one onto rewritable disks, until it becomes full and I create another branch. Then, the completed one gets burned permanently and the new branch gets rewritten each month. Since Lightroom is non-destructive, you know that you never need to update completed branches and you can make them read-only to ensure that.