It’s just that nobody really gets retribution for their evil deeds on this show with a few exceptions. They put Kristen’s brother (what WAS his name?) in jail for a long time but that was because he left the show. If they put them in jail forever, we wouldn’t see them again.
If you look at many of the characters and some of the awful things they’ve done (Sami is an excellent example when she was acting as Stan), they are still walking around scott free. Look at Victor who has had people killed and hasn’t even gone to trial or arrested. So, I don’t think it’s a case of not giving EJ his just desserts, it’s that they can’t really do anything to him and still have him remain on the show.