I don't understand the crux of this fellow's argument. If we can engineer and then print a fully functional cell, one which perhaps performs a function radically different than found in any natural organism, then what we're doing is no longer synthetic biology -- it's nanotechnology. In this case, we're building nanomachines, not cells.
Synthetic biology's appeal is that it leverages nature to do all the heavy lifting -- we don't have to engineer functions from the ground up, but only find similar designs in nature and then tweak them for our purposes. Furthermore, in synbio, we don't actually have to build anything, but only design it. We let nature -- which can assemble cells extremely efficiently, through a process it has been refining for the last four billion years or so -- build our systems for us, once we've translated them into the language of genes. If we have the ability to build our own nanomachines from the ground up (understanding, of course, that the cell is simply a specialized nanomachine built by nature), there's no need to constrain ourselves to the limitations inherent to nature's design. At that point, there's no reason not to divorce ourselves from the "biology" part of "synthetic biology."
Synthetic biology's appeal is that it leverages nature to do all the heavy lifting -- we don't have to engineer functions from the ground up, but only find similar designs in nature and then tweak them for our purposes. Furthermore, in synbio, we don't actually have to build anything, but only design it. We let nature -- which can assemble cells extremely efficiently, through a process it has been refining for the last four billion years or so -- build our systems for us, once we've translated them into the language of genes. If we have the ability to build our own nanomachines from the ground up (understanding, of course, that the cell is simply a specialized nanomachine built by nature), there's no need to constrain ourselves to the limitations inherent to nature's design. At that point, there's no reason not to divorce ourselves from the "biology" part of "synthetic biology."