That's an interesting point. I think a great solution could be to make streak badges private only! If the point is to encourage writing, just personally seeing this would do so. I have habit apps on my phone that run on similar concepts. I use them because it does actually work. But the world doesn't need to see that info in order for them to encourage action from me.
Some public badges could be community-based type badges. Like the SheCodes one. Or maybe a badge for someone who helped someone else. Or badges for Mentors because that's a really great thing to do.
Things that encourage positive actions towards each other. :)
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.