Why does SD default to "do not Copy" button?

[ncmphoto]

Just curious, but this almost gets me every once in a while, and I would think it's confusing for newbies. If I launch SuperDuper and choose source and destination hds and give admin ok to the operation it would seem that I want to do a backup, doesn't it? So why does the actual window where you start the backup have the "do not copy" button as the default instead of the "copy" button?

[dnanian]

Because it's good design (and part of the HIG) to default to the 'non-destructive' action.