You can still sign up for Quora accounts without a social network OAuth. I just did. It asked for my email, firstname, and lastname.

When you post questions or answer, you can also click the "anonymous" checkbox to remove your name.

yet they require you to have a real name

if you don't, they'll flag you and until you update your name, your account will be frozen (you can read and follow but can't answer) and all your previous answers hidden

The problem with reddit is that it's hard to ask random, potentially "dumb" questions. You have to find the right subreddit, and if you're wrong you'll just be downvoted and receive joke responses. Even in the right subreddit many questions will get instantly downvoted by people browsing /new/. Quota has none of these problems.