When Feng Zhang spoke at my school, it seemed that the use of patents was to prevent unethical modification of human embryos, but that hasn't seemed to deter scientists in countries where IP is not recognized (China).
If that's a genuine ethical issue then patents would be woefully inadequate at preventing it, since they would only provide a time-limited block. To actually fix things you'd need actual regulation, at which point the patent goes back to being bad.