Because this is how you get a "Stop Killing Humans" petition in the EU, and a "Right to Medical Care" movement in the US.
DRM has no valid purpose for the legitimate law-abiding customer. For them, they just get suck with an inferior product compared to the "free" version from the high seas. I.e. It's all about control, and profit. Which runs directly against the concept of "do no harm" in medicine.
We already know what the likes of Monsanto would do with this tech: Ban anyone from having kids without ordering from their catalog, and suing anyone who got a contaminated germ cell with one of their modifications. Even those who were targeted for contamination by their neighbors intentionally.
We already know what the likes of Hollywood would do with this tech: Sue into financial ruin anyone who could even remotely have looked at it without their permission, despite the lack of uniquely identifying evidence.
We already know what the likes of video game publishers would do with this tech: Mandate it in everything, and try to shove it into the most critical invasive areas possible without any regard for quality or safety of the end-user.
We already know what the likes of John Deere would do with this tech: Lockout "unauthorized" third party healthcare providers and mandate expensive technician call outs that can take too long to actually happen and kill your loved ones.
Now apply those outcomes to humans:
Monsanto - A real birth rate crisis due to letting for profit companies dictate when and how many kids your citizens are allowed to have. Nations wind up trading all kinds of political favors for birth licenses.
Hollywood - Doctors afraid to treat their patents, due to legal liability. Massive tracking of everyone becomes mandatory. (Hope your DNA has a constant internet connection to re-authenticate, or you might suffer from sudden death syndrome.)
video game publishers - Cancer all over the place. All of the cancer, all at once. BSOD takes on a whole new literal meaning.
John Deere - Healthcare becomes unaffordable worldwide. Scams and real options (for those willing to pay the price) that promise to let you "cut in line" for faster technician visits become the norm. Drastically limiting access to healthcare worldwide. (Especially in poorer countries.)
TL;DR: The amount of ways that the use of this tech can go unethical far out weigh those that are ethical, and it's not even close.