One of Wikipedia's main behavior guidelines is a fairly similar idea, "Assume good faith": https://en.wikipedia.org/wiki/Wikipedia:Assume_good_faith
I somehow prefer "good faith", even though it's meaning is harder to parse when you first hear it. The 'faith' does a better job of hinting at the emotional component of the concept.
It is SO easy to misread things, which is one of many reasons that AGF is so important a principle.