First off, no idea is a bad idea and we appreciate the suggestion... however...
Nobody is being forced to use it. At any time you can toggle the service off completely and the processes will not run at all. In fact, I have a personal machine that only runs deluge as I have opted to turn off rutorrent and irssi. Older versions are options and are not in the slightest unused as (believe it or not) there are still some trackers out there that require older versions, this goes for users as well. Only b/c one person fails to see why these are included does not negate the fact that others do sometimes prefer them. We are not here to stow away options from the user-base.
Removing ruTorrent from the installer and then turning around and building in a package installer for the software is a complete waste of resources and time. A seedbox is a seedbox and ruTorrent just so happens to be what we include as a default application for torrents. Deluge is only used by a small margin of (mostly racers) users in the torrenting community.
We will keep ruTorrent as the default application at this time as it is what most users are aware of... new and old.