I'd suggest that a group of people involved in the process have a financial incentive to advise defendants to waive their right.

Beyond that, the system endears so much legalese and judicial "red tape" that preparing a defense might not be realistic in only 30 or 45 days. Since this effectively destroys that right, it could be argued that this outcome is intentional. Alternatively, a bloated bureaucratic judicial system rides atop the mountain of regulation and law created by legislators, and has made a fast defense impractical.