There are ways to obliterate from git[1], but to your point of complexity, its not as easy as just "git obliterate some-file"

[1] https://help.github.com/articles/remove-sensitive-data

Correct, I acknowledge that:

On the other hand, once it’s public, it’s public for good. Git makes cryptographic guarantees that ensure that if someone tries to rewrite history to obliterate a file, every clone of that repository will notice at the next fetch (perhaps to the ire of your fellow developers).