From reading this thread, the issue seems to be that OP is confusing two things: (1) the rating assigned to a puzzle, and (2) whether your attempt at a puzzle is rated or unrated, meaning whether or not the result will affect your puzzle rating.
Puzzles that don't yet have a rating assigned are labeled as "pending" and their rating shows as "-" in your puzzle history. If you get one wrong, you gain 1 point rather than losing points. There are only two of these in the screenshot posted above.
In contrast, "unrated" means that this particular attempt is not rated and the correctness of your solution won't affect your puzzle rating. As Martin said above, if you get a rated puzzle wrong and retry it, your retry won't be rated (it will say "unrated" up top) and you can play around with it without worrying about your rating.
As a non-premium member (for now), I like this system, because I do want to retry my failed puzzles until I understand why I got them wrong, but I don't want these retries to consume one of the 5 rated puzzle attempts that I can do each day. Also, it seems sketchy to be able to try the same puzzle repeatedly and gain rating points for getting it correct eventually.
Puzzles tend to be group in broad windows.
1000 -1200
1100 - 1300...
1200...
Due to the complexity of chess, a person could easily go from, for example, 1100 to 1300 just studying tactics...
..and a different player could go from 1100 to 1300 just studying positional chess.
Ideally, a player should study both at the same time.
I think it was in the 90's or early 2000's some player was hawking a system in which a player could go from 1300 to 2100 just studying tactics alone. He did that. He wasn't selling anything, but he had a blog.
No doubt it could work, but it wasn't a balanced way to get better. He admitted he hit a wall, because players rated 2200+ could easily win because they never gave him a chance to use one of his monster tactics. If they didn't win from a tactic, the higher level players just ground him down in the endgame.