I agree this is bad but why is it bad if an employer says they want a genetic workup done and just don't hire you if you say no? I just wouldn't take the job an

I agree this is bad but why is it bad if an employer says they want a genetic workup done and just don't hire you if you say no? I just wouldn't take the job and I don't see what's wrong with that. If you're employed as a test subject for a new cure to something getting a genetic workup seems very reasonable and is about the only time I'd acctually say yes to something like this. That's really the only case I can think of where this makes sense. Why do companies actually want to do this? Do they think people will still work for them if they do?