Here's what won't happen: you won't give your login credentials to a third party. That's because your browser won't read any cookies from the original site, and Genius prevents you from typing into web forms.
The author uses technical language without talking about what people do, how people interact, and what people care about. Instead, there's much ado about a variable called "clickjacker" -- eliding the fact that www.theverge.com installs a slew of clickjackers of its own. Is Genius evil because of a variable name?
Let's find out how Genius' CSP changes can affect human beings, THEN write 3,000 words about it.