re: Project Management Professional Accreditation

As it relates to the OP, obtaining a PMP designation does not ensure that you will magically become a good project manager - it just means that you can pass a test. However, the concepts that PMI preaches are undoubtedly good for projects (and business in general) if applied correctly.

I can't vouch for the competence of the PMPs that you have dealt with, but I would say that a similar low number of "people doing the real work" have a solid sense of the big picture as it relates to the company's strategic schedule and budget needs, project risks, and appropriate communication.

Successful projects tend to be those where both sides have a good understanding as opposed to a project manager forcing arbitrary dates and budgets and front line employees ignoring them.