"I challenge you to find a public company with a similar policy. I have been around a long time, and I've never found one.
"
Google's policy was, for years, identical to this :)
(It is only slightly more onerous now, in that we ask to see the first few patches you contribute, mainly the result of too high a rate of unreasonable judgement generating actual issues, which I chalk up to statistics and having a really large number of engineers now)