Because you'll have to review it, and Go's design limits the number of ways it can go wrong.
Code is free, sure, but it's not guaranteed to be correct, and review time is not free.
Code is free, sure, but it's not guaranteed to be correct, and review time is not free.
... write the code yourself?
I think many many people just skip the "review" step in this process, and assume they're saving time. It's not going to end well.