It’s just another frontier of science with its own risks and rewards. Sure there are ways to use or produce it immoraly, but it’s not inherently immoral.

DNA is just a polymer, one we have some capabilities in manipulating. It is not inherently alive, nor do it’s instructions necessarily have to relate to something living. When processed by living things they contain instructions on producing proteins, but they don’t need to be processed by living things and could be used to store arbitrary information in a dense environment.

Neurons, while cellular are not alive in and of themselves. They require a full host to operate, but are essentially weighted dynamic switches (interneurons), environmental inputs (sensory neurons), or outputs (motor neurons). Devoid of a host they are inert, but provided the right artificial environment they can function. “Function” just means operating in that input, switch, output mode though–it doesn’t mean being alive as a macroorganism, being sentient, or having feelings. Using a handful of farmed human neurons to play Doom is more an exercise in controlling the dynamic environment needed for the switch connections to be made, therefore, than an exercise in enslaving a conscience person.

Nature has been the source of inspiration and development since before the dawn of humans. I see no reason it should stop at the doorstep of biology–especially when the extent is cultured environments developed in a lab to be a facsimile of a part of a living thing. A part of living thing does not a living thing make.