Certification is just a ploy by vendors to get more education business. While concepts and tips learned in training courses will certainly enhance one's ability to become a Sybase Certified Associate or Professional, courses are not required. In the case of the PowerBuilder developer program, its launch in 1993 was in direct response to requests from customers for such a program. Exams are created largely through feedback from Sybase's PowerBuilder Review Committee comprised of senior PowerBuilder experts from Sybase, customer organizations and education partners. The Committee recommends the questions to be asked - those that will fairly measure abilities.
Certification costs too much - the cost of training, exams, and time away from the office.
Achievement in any discipline does indeed take time and commitment. Those that excel typically acquire as many tools as possible to increase the probability of achieving their goals. And in the long run, these up-front costs are more than paid for in increased system effectiveness, productivity, service quality, and return on investment. Certification is a commitment toward excellence, one of the tools a professional can use toward becoming the best. Even if I could afford to support certification for one of my developers, I can't afford the ongoing cost to maintain it.