User Experience: Does your "flow" make sense?

I recently read an article on jobs to avoid.  In one case, it said "avoid job x as it's projected to be outsourced more and more and instead try job y."   I thought to myself... how odd... job x and job y are the same thing... aren't they?

So I searched "x vs y" on Google.  The top result was in a box and based on the snippet, looked to be exactly what I was looking for.

I read the article, a user-generated submission and thought it was spot on and confirmed my theory - x and y are the same thing and this other article is written by someone who doesn't know what they're talking about.

At the end of the article was an opportunity to provide feedback:

So I clicked "I found this answer useful."

Immediately, I was taken to a new page that simply had this (plus their standard header and footer):

I immediately hit the back button because it was not what I was expecting.  Had I clicked the wrong thing?  Nope, trying again resulted in the same screen.

What have they done wrong?

They have failed to set expectations.  In soliciting feedback, there's no indication that an account is required (or that one will need to be created to provide feedback).   This could easily be solved with the addition of a few tweaks:

1. Replace the signup page with a popup/overlay modal so you never leave the page you're on.

2. Indicate on the signup prompt that an account is required to leave feedback.

3. After "Did you find this answer useful?" simply add  "(Create account or signin to leave feedback)" if the user is unauthenticated.

Even if all they had done is step 3, they'd probably get more signups.

I bet if they were to look at their page analytics, they'd see traffic come in from Google, read an article, click on the feedback buttons, see the sign up screen, go back, click on the feedback buttons, see the signup screen again and then the session ends.

The lack of clarity is costing them the chance to create a relationship with a brand new user who's never heard of them before but would have been acquired simply by the nature of the user-generated content.