I know projects that do or did put their production database credentials, which had full read and write access, in git.
And no, thats not a clever thing to do, neither is there a good reason to do it. But people do things you do not like and theres little you can do about it.
I would like to live in a world where you were right, but I am not. Sadly.
[Edit] dumps though are another thing. Not seen that, yet.
You need to open that link incognito. (If clicking through from HN)
The site you linked to detects if the referrer url is HN and instead displays only an image saying "HACKER NEWS - A DDoS MADE OF FINANCE-OBSESSED MAN-CHILDREN AND BROGRAMMERS" instead of the content you are trying to link too.
A third reason would be finding a security flaw in the source code and exploiting it.