There's been a lot of debate about whether or not you should get a Scrum Master Certificate. There’s even more debate about which certificate to get.
The best aspect of a generic certification is that there is at least some evidence that the person who has the certification has heard the basics of the craft. As an employer, you can’t always test each applicant for basic knowledge. The notation of a certification on your resume can speed things up.
Of course, if the practice is complex--like brain surgery--you want to make sure your applicant knows more than the basics, so rigorous certification and licensing processes are needed.
One of the positives about Scrum certification, versus, say getting a license to practice medicine, is the certification is not very expensive. You can get an online certification for a few hundred bucks, or attend an in-person class and test for about $1,200.