I used to be against certifications until 6 years ago. The main reasons were that:
I used to, and I still do, see many certified people who don’t know much about the subject. The certificate doesn’t really prove anything, so why bother? And,
I used to be good in the topic, and I didn’t feel like I have to prove it to others by passing an exam and getting a piece of paper (or PDF file).
But I gave up! You know why? Because…