In most programs the point wouldn't be to teach the specific technology, but to teach something like "interactive media design/programming", or variations on that. To keep things manageable, though, often courses will pick one environment for the examples/project to be in. Flash is a common choice; HTML5 and Processing are also used semi-regularly. Courses catering more for CS majors might use something lower-level like raw DirectX or OpenGL (possibly via a wrapper like Glut or SDL). You typically can't avoid choosing some technology, whether it's Flash or OpenGL, even if the point of the course isn't specifically to teach that technology's API and quirks.