Well, it doesn't hurt to improve your knowledge, there are always some things new to learn, otherwise, the life would be boring.
The reasons are because it could help with my job, ...
If you're looking to get certified for the purpose of getting promoted in your current employment - then simply ask your employer will such certificate help you in any way.
If you want a certificate to find a different job - then, I believe, there were few better known and established universities offering similar courses online.
If your goal is to self-improve, then you can learn for free and most of all - get involved/contribute to existing open source projects. Such would be worth much more than most of certificates.
As for Blockchain Council - I've never heard of it before and am not familiar with any of the Key Members listed on their site. Frankly it looks just like a money grab project (affiliate programme, 30% discount, listing ICO on top of their offered courses, strange quality of key members photos), meaning they charge you for knowledge that is already available for free, just to later reward you with their certificate (anyone can produce their own certificate to whoever they like for anything). Pointless imo.
