I think the idea is that players should be able to settle their differences in-game without having to resort to complaining to a GM every time someone tells another person they're bad at their class. When they changed the rule to allow players to complain to GMs over being offended by just about anything, it put a greater need for a system like you're requesting. I'm not saying that some players are undeserving of being reported, but I don't think it's as necessary as some people make it seem. Unless you're in limsa, you shouldn't be seeing anything too bad in the chat and you can disable emotes from appearing in the chat if it bothers you. Is it really that problematic that this system needs upgraded? I don't know, I have only blocked a few people sending me links to phishing sites but that stopped when trials were cancelled.

With that said, they could improve their existing system. From what I hear, if you delete someone as a friend, they can still see you as a friend even though you deleted them. Kind of weird of a system unless they fixed it. I think the solution isn't so much about how to report other players, because if it were easier it would cause more issues. Instead, I think they need to upgrade their chat system so it allows filters including custom filters that you write yourself. Don't want to see the "Great googly moogly" party macro? You could add that to your filter too. This would alleviate issues more permanently than applying a band-aid for complaints.