Grapher has apparently been abandoned by Apple. My guess is that the original developer(s) have an agreement with Apple that Apple would not maintain it (get rid of its many, many, many bugs and write a decent Help file is more like it!) so that the developer(s) could market it commercially on their own without competition from Apple's own bundled software. (E.g., read this: http://www.pacifict.com/Story/.)
Filling out the feedback form that someone linked to is totally useless. Mac owners have been telling Apple about the many, many, many bugs in Grapher for approximately 10 years, so they are fully aware that it is seriously flawed. The problem is, they don't care.
This has led to a wholly unacceptable situation where Apple is dangling this piece of fruit for prospective customers but the fruit is rotten to the core!
This is really not necessary, and very unprofessional of Apple. The commercial descendant of Grapher has gone through multiple versions; it's now at version 4.0 with many additional features. It behooves Apple to at least debug Grapher and rewrite the Help file so that the program conforms to the documentation, and so that the user can access the features of Grapher from the documentation itself.
