All right, I'm taking arguments in favour of hard translations now. Go on. Give it your best shot.
I'd say something about how typos are just as likely in soft translations, but you can just edit them after the fact...
Could say something about the possibility of typos also existing in the original language that the folks who can't read it simply can't spot, but that's irrelevant...
Best I can come up with is, if someone wants to save a page of a hard translated comic, they only have to save the image and don't need to worry about copying a transcript.