While I don't agree that a PMP certification makes better project managers, I agree that it's important, here's why:
- Better pay: PMP certified project managers are better paid than non PMPs.
- More recognition: It's a fact (and a sad fact, in my opinion) to say that project managers with the PMP certification are thought to have better skills than those who don't have it.
- Competition: When two project managers of similar work experience apply for a job, and one has the PMP while the other doesn't, the company will usually give the job to the one who is certified.
I don't think it's true that every other PM has a PMP at the moment. True, there is a lot, which means that the PMP certification is becoming more of a standard and more of a "must-have" certification for project managers. So do you want to be left behind in this competitive world, or do you want to join the list of PMP certified project managers?
It's your choice...
Note that the importance of the PMP certification is dwindled by the experience of the project manager (so the more experienced the project manager is, the lesser the importance of the PMP certification).