Most Superfluous Certificate Ever?

I just picked up this block, with certificate, for no reason other than curiosity. As near as I can tell, the other close color option isn't particularly valuable, either. The other color options wouldn't really be confused with this color, as far as I can tell.

"The Expert Committee determines this block is genuine." No kidding.

Why would someone bother to get a certificate for this block? What am I missing? Was this a more widespread practice in the past?

Sadly, I'd suggest that someone, over time, put together a certified collection of the shades of this issue, and the collection has been broken down. The SG Specialised lists seven shades for this stamp, and some are very valuable. The cert may be just to confirm the shade. This may be a case of a certificate to exclude rather than include.

I just think he needed proof it was a block of four, perhaps numerically challenged.

Bee, if it was a PSE cert I'd suspect you were right on the money, but this is RPS...

jubilee, you're probably right. You'd maybe get all the shades verified just to show you'd done it. There's not much likelihood of confusion between this and the deep dull, or bluish, or whathaveyou, so I'm going with your explanation.

Collin