Disqus violating Twitter TOS and users trust

In the dark of night, without notifying their users/customers, Disqus made a change that negatively affected their users and their users' commenters.

Whereas before, you could login directly to Twitter or Facebook to make a comment, now you are required to create a Disqus account before being allowed to login via Twitter or Facebook ( http://help.disqus.com/customer/portal/articles/1165015-merging-your-social-login-to-a-disqus-account-has-important-benefits ).

That being said, Disqus still utilizes the Twitter and Facebook marks. When a user clicks on the Twitter/Facebook icons, after a series of redirects, they are prompted to create a Disqus account. This pretty clearly violates the Twitter "Developer Rules of the Road" (i.e. Principle #1 Don't Surprise Users). A user clicks on a Twitter icon and is prompted to register for Disqus...how is that not "Surprising users"?

Over a number of years Disqus has done a great job of building the trust of businesses to use their product. Now, if a business uses Disqus comments, when a user goes to login with their social profile on a businesses website, they are prompted to create an account with a third party.

If a website owner doesn't ask users to register to make a comment on their website, why does Disqus?

I guess the options are a) disable social service logins, or b) switch to a different service (Intense Debate?). While, c) Disqus letting us pay to disable this "registration step", would be acceptable too...ironically, that seems the least likely to happen.