I don't mind it, but I feel it's unfair to those who want to read if they don't have an account.
I feel like these online stories should be treated like actual books and if you want to read a book, you don't have to subscribe to it or have to be a member of something just to read it.
I also believe that if they have low views on a story labeled that and they're wondering why, then they should allow everyone to read. As I had mentioned before, I feel even these types of stories should be treated like books; therefore they should not stop someone from reading it.

Nothing. I personally don't do it.
I'd rather have people comment on the story than subscribe and be silent readers.
But I think it might be a way to prevent plagirism, restraining the people who can access your fic.