Why are news websites logins almost always broken?

Is it just me or is it usually impossible to leave comments on these crappy local news websites because their login systems are almost always faulty and/or completely broken? You know the deal - you type a comment, click submit, it throws up a dialog box asking you to either register an account or sign in with Facebook, Google, Yahoo, Twitter or whatever, so you choose say Google, click "agree," it asks you to provide a user name, click "ok," which then takes you back to the "sign in with Facebook, Google, Yahoo, Twitter" screen again, and on it goes in an endless circle without actually signing you in. Actually I find this on a lot of blogs and websites in general. Is there some kind of universal library of website login code somewhere that's just hopelessly buggy?