Earlier quoted context omitted.
That's because you seem to be halfway through making an account and they want you to finish. The actual behavior of Quora, if you aren't midway through account signup is: if you go through Google search it shows you the page promised. If, from that page, you click on another question it will open the second question but give you the sign up modal. You can bypass a signup modal and get the normal page by appending ?sh…
Please see the posted video above. It's very clear how Quora forwards me to sign up page right after I open the link on Google. I never tapped on anything after I got to that page. The behavior that you guys are suggesting is mostly how it works on Desktop computers. Try searching for the same on Mobile phones. PS: Also, do you really expect users to alter the link on tiny mobile screens?
I don't "expect" users to do anything, I was sharing a known workaround in case anyone was interested.
EDIT: I just created an account to see what happens. You are logged into a new account. Maybe you accidentally logged in with Google?
I created a new account with a fake name and email. No email verification. After the fake name and email is entered they ask you to follow topics (which is the screenshot you are seeing) and once you pick 10 your account is "complete" and they will let you look at the answer.