A copy is just an identical image. There is the possibility that a single virus could destroy an entire set of systems and copies do not give rise to variety and originality. Life perpetuates itself through diversity and this includes the ability to sacrifice itself when necessary. Cells repeat the process of degeneration and regeneration until one day they die, obliterating an entire set of memory and information, only genes remain. Why continually repeat this cycle? Simply to survive by avoiding the weaknesses of an unchanging system.
It can also be argued that DNA is nothing more than a program designed to preserve itself. Life has become more complex in the overwhelming sea of information. And life, when organized into species, relies upon genes to be its memory system. So, man is an individual only because of his intangible memory... and memory cannot be defined, but it defines mankind.