It's in the article you linked to, but I suppose Google expects everyone to use their Personal Blocklist Chrome extension now:
https://chrome.google.com/webstore/detail/personal-blocklist...
You can not blacklist entire TLDs, just individual subdomains.
Thanks to ICANN (and others?) there is hundreds of TLDs that are 100% full of spam. And they all are able to game the system.
Google has lost the SEO War IMHO.
If they are not willing to innovate they should be broken up via anti-trust.
The "Block foo.com" links don't appear in the search result anymore, but if I visit the website and block it through the extension pop-up they are then eliminated from the search results in future searches.
IIRC the OFFICIAL "Personal Blocklist" was broken for a long time due to this.
AFAIK there's still no way to block entire TLDs.
So basically Google doesn't give a shit about you!