wilderness - 3:08 am on Dec 25, 2012 (gmt 0)

Wayback is useful when we find someone who scraped our content say 2 years ago, and we have to show their webhost what our site looked like 2 years ago, and also that we had the content up first.

I keep my own site archives, I don't need them.

Ditto.
Any person (webmaster or otherwise) that uses their computer extensively for storing data better have a regular backup method in place.
I have two, which is done on the first of each month.

If you haven't read NOARCHIVE.NET [noarchive.net], go there now and find out more.

This bears repeating.