Who said anything about not trusting your first system? You keep making assumptions about what others are doing. These assumptions are wrong.Are we talking about the second rope you hook into with when you unhook the first so you are constantly hooked in? We are not industrial climbers. Hell you could wrap yourself in bubble wrap and never leave the couch.
All I was saying was, if you don't trust your first system, out shouldn't be climbing on it. No need for a back up. We are climbing 20 feet up a tree and sitting, not swinging, not cutting, not welding, not rubbing our tethers on jagged metal. Climb how you want, but if you have redundancies, oh should check your methods.