The problem with this version is that it requires interpretation of another person's intentions and attitude - something we're exceptionally bad at and which is causing a lot of drama simply through misinterpretation.

The version that says "Do unto others as you would have done unto yourself." does not have this problem. Furthermore it scales better because you have to perform the underlying calculation only once as opposed to once per encounter. I get that this approach does not provide any guidance for handling abusive people, but I would argue they can be dealt with on a case-by-case basis. In all other cases, treating people like you would like to be treated should be a reasonable default.