Its not that their links weren't showing up for purely crypto searches; they were almost literally smeared off the board.... and I personally have serious doubts you read the article originally linked at this point.
Big snip of quote, but yeah I read it. Not impressed. Every time Google makes big changes to their results people complain that they are being targeted.
They come up with the same fancy charts and graphs.
Stop trying to game the Google algorithms, put up relevant content and don't use SEO hacks. I have seen the same thing over and over again from sites that got a big drop for 15 years. Left, right, center, political, automotive, healthcare, whatever. It's always "we were targeted because we are [fill in the blank]" It's kind of like kids blaming someone else for spilling something in the kitchen.
It's an algorithm, it doesn't get happy, it doesn't get sad, it doesn't get hungry, it's just a program. If you think it's personal stop being so sensitive.
Side personal note, if your web business is so reliant on 1 source of clicks and hits and revenue that loosing it will cause you to close then you should not be in business.
That's juts my view having been doing web work since Windows NT 3.51 on an ISDN line. Many people will disagree because Google is the 800lb gorilla in the room. But that's just because they are too lazy to work at getting Amazon, Yahoo/Bing, etc. to all work together.*
-Dave
* Sometimes it's almost impossible without a lot of work. Things that Google will give you a downgrade for are good for other search engines. Too bad, figure it out and deal with it. If you are doing web content that's your job.