Why is adding comments while attaching files so important in Confluence?

First of all, in Confluence adding attachments is very easy. You can drag and drop or
as follows:

To attach a file to a page from the computer's (or network's) file system:

Choose Tools > Attachments.
Choose Browse and navigate to the file.
Select the file and click Open.
Add a descriptive comment for the file (optional).
Choose Attach more files if required.
Choose Attach.

When you view attachments, shown as below:

The name of the attached file may not be enough to tell the content of it. Many times, you create a page, after a while when you view the page & attachments, probably you forget why you added it, etc. Luckily, confluence supports attachment properties (as shown in the above image).

These are:

1. Name
2. Size
3. Creator
4. Creation Date
5. Comment

In the image, only first attachment has a comment, and it is also meaningful for viewers except the creator :) However, there is no way to make comments required for attachments. At least I haven' t found it yet ;)