This whole mechanism is a backdoor to execute code while interpolating

  DB<106> print "@{ [`ls`] }"
babel-14425MIs
 emacs1000
 keyring-JbFqiG
 orbit-lanx
 perlfunc.pod
...
[download]

Thats a clear violation of the line between interpolation (like in s//$x+1/) and evaluation (like in s//$x+1/e)

Updated example!