This sort of problematic update is a huge discouragement to principled owners of good quality sites to invest. The ROI on the average site is probably near to zero to begin with. But if sites see years of investment knocked out by algorithm changes, for reasons which are not explained, which do not reflect their intuitive perceptions of 'high quality', and which SEOs can form no unanimity of opinion on, why would any sane person invest?
Frankly, it makes operating on the web like doing business in a 3rd world country where operating environment is subject to sudden, unpredictable, and arbitrary shifts. Result? Entrepreneurs under-invest in 3rd world countries (which is why they're 3rd world).
The irony is, you guys came from Russia, and have accidentally re-created an environment which replicates some of the discouragement to entrepreneurship present in your home environment! You seem to be creating a 3rd world environment where 'fixers' rule ( = in the web context, SEO hacks). Of course, there are entrepreneurs willing to work in such environments, but you will drive away the hard-working and principled site owner with a genuine commitment to providing high-quality, honest information, especially if he is disinclined to spend large sums on 'fixers' (=SEOs)
I am not saying that accurately assessing site quality by machine is easy, in view of the human desire to ‘game the system’. You have my sympathy. But this time the damage has been enormous.