True, you can do high speed photography without a PC. However, there are sound arguments for incorporating a PC into your HSP system.

Timing :    The PC provides the hardware for digital time delays
Control :    A simple and inexpensive control system can be developed for the entire HSP system, not just the flash trigger. This can be very useful for conducting HSP experiments on ones own.
Cost :    In the minimalest approach, using the PC is probably less expensive than the stand alone electronics version (excluding the cost of the PC)
Project :    As a PC interface project, well, it's as good a project as any other you'd care to mention.