SCPD is generally aimed at people with training budget money to spend that need some kind of certificate to show for it. There are a few more (Stanford Advanced Project Management some in financial engineering and risk management, some in bio engineering, IIRC).

The OpenCourseWare classes, which have a lot of spiritual overlap and more delivery system lap with SCPD, are aimed at everyone else.

Oh, the SCPD GPA requirement is not particularly strict, it seems, if you have a professional background in the area or a degree from ``top tier'' school or such. They just don't want to let anyone in who will reflect particularly poorly. (Which you might argue the corporate orientation defeats, but that's a different argument entirely.)