Which is to say that I've earned the right to use machines by proving that I can function without them. The Mathematics Department at Moorpark College has no departmental policies governing calculator use. That is, calculator use in any particular section of any course is solely at the discretion of the instructor for that section. Courses in which graphing calculators are required are so designated in the schedule of classes. While no such mention of such is made, instructors of these courses tend to require, either directly or indirectly, a particular band and model of machine.
Calculators can be expensive.
To require a calculator in a class increases the cost of the class and thereby inhibits access to the class. Of course, in this day and age, it is not at all unreasonable to assume that every college student already owns a calculator. Different calculator manufacturers configure their products differently. If calculators are to be required in a course, it seems only fair that some instruction on their use be presented. Different calculators are designed for different purposes, and are constantly subject to design enhancements.