[hrktb]

Could your question be generalised as “why would I want to opt out of X if there is any potential to help beneficial Y” ?

For me the issue is not that Y will be good, more that there are countless of potential research outside of Y that can’t be restricted and I wouldn’t agree with.

23andme for instance is not saying that their data will only be used for research that most people agree with. There is no “don’t be evil” mantra they harbor. And by definition there can’t be anything that 100% agree with and they can’t ask everyone for every use.

In that respect I think people should be able to contribute their data themselves to Y, without a man in the middle choosing where else the data should go. Short of that not contributing anything seems a sensible position.