Programmer certificates would be bad for Perl. The problem is, without a large commercial organization driving the adoption of new releases of Perl, the widespread acceptance of certifications would freeze the evolution of Perl. If the major force driving the acceptance of new revisions of Perl was whether or not employers were accepting certifications in that revision then the certification organization would control the language definition. History has shown that the controlling organization will always opt in favor of definition expansion, code bloat and mission creep with the new additions favoring duplicate capabilities rather than radical changes.

Programmer certifications would cause Perl to fork. This would be a bad thing. Standardization of a language leads to bloat which leads to language subsets. We saw this happen with Algol, Fortran, Forth, and Ada. It is more important for the life of the language that we be able to throw out dead constructs as well as add new syntax. Certificates would not allow us to do that.

For a interesting historical perspective see: The Law of Standards