Sure, but the same is true for unsigned commits as well, isn't it? Or can you modify the commit metadata without changing the commit hash in those cases?
My question was, is signing the commits really useful? Isn't it just as hard or easy to scrub you from the repo history regardless of whether the commits are signed or not?
Technically yes, but the price is too great - everybody who has cloned the repos will now have to nuke their local copies too.