Curious: why move a trojan to the chest, rather than delete

[aob]

Avast found several viruses a/o trojans. For each, the recommended action was to move to chest, as opposed to delete. Intuitively, I would think I want to delete something bad, rather than moving it to a chest, no matter where the chest is or how secure the chest may be. So, why am I being recommended to move to chest?

[jdlenke]

If the trojan has tied itself to a critical windows file it may be necessary to put it back where it was in order to have your computer run again and find other methods of cleaning it.

[aob]

jd:

On its face, that makes sense, except at the end, when I am shown all of the bad things that have been isolated, I delete them all.

[fink]

Also, in case its' a false positive and maintaining the ability to submit it to one of the online multiscanners to confirm the infection.

http://www.virustotal.com/