I don't know what percentage of their articles were behind one then, or how that might've changed between then and now. (Well, except for the fact that clearly some of their stuff is public today since we're looking at it.)

If I had my 'druthers "paywall" and "register-wall" would be little icons on the submissions, and then people would choose whether to upvote the more-accessible source, whether the hard-to-read stuff was still important enough to comment on, etc.