Unfortunately, this had to be done due to the regulatory pressures.
The blog post actually felt quite sincere given that usually exchanges just glance over the issue of privacy altogether. Shapeshift has definitely been one of my favorite exchanges to use over the past few years, with all the KYC requirements on other exchanges. It's sad to see it come to an end, and their business will definitely be hit hard due to this - but it was a matter of time only.
Today, Membership is optional, but it will become mandatory soon.
I will probably continue to use it until this becomes mandatory, at which point I'll try find another site to use. If I can't I'll probably reluctantly hand over the docs, but as a last resort. It's really quite unfortunate given that it had the perfect mix of anonymity, trust, and convenience. An alternative will be hard to find for sure.