It's wild that this continual destruction of evidence is not only tolerated but SOP. It's just so convenient! Imagine if commit messages disappeared after 6mo!
There is probably a desire to make commit messages go away after 6 months. I am guessing that the lawyers aren't putting much pressure on engineering teams because nobody has thought to "discover" commit messages in a major case yet (whereas email is routine).
Well, the alternative is for every last written thing at a company--jokes, gripes, mistakes--to be scrutinized and taken out of context in court by an opposing side's legal team.