If you look up definitions of logical fallacies, one you may find is argumentum ad antiquatum (or some such spelling, I know latin not). The fallacy can be recognized by seeing someone is arguing that because something is old, it must be good. Tried and true does have situations where it can apply quite well, but when discussing the best option for now it is quite possible technology, thought, or morals have changed since the current/old solution was implemented (and one must still ask whether the current solution was the best solution at the time it was implemented or any time since).