They already release the 7 million people's data - to the same extent the hackers got it - to anyone who manages to upload a sufficiently similar genome. There's no additional data privacy concern in releasing it to hackers or Equifax or the FBI or 4chan or the Washington Post. 23andMe limit access to it for commercial reasons, not privacy ones.
But you only have one genome, so you will only ever see a very small subset of that 7 million (I’m assuming that’s how it works, I’ve never used the service). Now you have access to 7 million records at the same time, which is much more powerful in terms of what you can do with that data.
More powerful, but mostly you can do good things, like genealogical research, not bad things, like identity fraud or credit card theft (which you could do if you compromised the 7 million accounts individually).
It's better for the world that that kind of aggregate data is public where anyone can use it, rather than exploited by 23andMe or sold only through data brokers.