Or because bad légal documents become obvious immediately, while bad code has a 2-3 year incubation period.
A key difference is that law is an actual profession. It has qualification, continuing professional development and licensing requirements, and personal consequences for getting it wrong. None of these things are true for software development.
In both cases it looks perfect and it works right up until it doesn’t, usually for the same reason, entering an unanticipated state.
https://www.nbcnews.com/news/us-news/think-commas-don-t-matt...
(Actually, it only just occurred to me, lots of laypeople are going to use these to draft _wills_, aren't they? That should be entertaining.)