What about the thousands of people with imporant data that could be attacked in the coming days using this exploits, but can now protect themselves from it knowing this?

It goes both ways. As they said, this is active in the wild and many are being hacked AS WE SPEAK completely unaware of it. Imagine you had some information that is worth millions of dollars on your computer who is vulnerable to this. Now that you know, the first thing you'll do it turn off your computer or find a way to protect yourself. If they hadn't released it, you could've been hit in the coming week or month or however long it takes Microsoft.

As you can see, this isn't a black and white problem.