I wont reply from the point of view of a mod, but as me as a RPer lol. I actually still have fun when I RP on the site. Sure, there are times where I want to just say **** it and leave. Sometimes the members are annoying, sometimes mod work gets overwhelming, sometimes RL prevents me from being as active as I want. But I still find fun in the RP. I like creating fighting styles, creating customs. I like proctoring tests, teaching certain fields. I like battling a lot, it's always fun. Most of all, I like roleplaying, acting as a character and doing what I think they would do in that situation. As someone who likes reading and writing, it's fun to act out a role at times. I love the Ninja World just as much as I dislike it; it's an open sandbox where you can RP almost however you want, but it's always so confined to just randomly waged wars. You can RP as a king of a minor village if you wanted to, even as a prisoner or a historian. To me, the RP is always fun. Sure, I might sound biased as a moderator of the RP saying that, but I still find it to be fun.
Proctoring tests are always fun for me, because I usually limit myself even more to act just like the characters I have, sticking to just their elements and sometimes jutsus and mannerisms and methods of attacking (i.e. sometimes I start tests with Naruto by making a clone and rushing forward with a Rasengan). I like to see if people can stay in character as well and match or raise my pace in tests. It doesnt always happen, but when it does, I tend to reply quicker and have a lot more fun. Training in fields besides the base 5 fields like Sharingan, Sound Release, and Fuuinjutsu and Taijutsu fields are always fun for me to teach because most times, it's largely theoretical work and at times, my knowledge of those fields grow as well. Most of my students have fun and learn a lot as well (at least I hope so), which is rewarding on it's own. Making customs is a big fun of mine. Sure, a lot of my potential ideas are shot down before submissions and some more are declined upon being submitted, but I still love trying it. Training, my own trainings as rare as they are, are fun as well, something I've liked since I first joined back in 2009.
But the greatest fun is the Ninja World and the people I RP with. I always have had fun RPing with some members, such as the old Akatsuki members when I was originally a member the first time (Lili, ZK, Gobi, Nagato.., NK, etc), especially when we used to create mini arcs and events of our own to RP. Even my fight against Lili was fun, even if tedious at points, and we collaborated on a future RP arc as well, continuing our RP to make it more fun and dynamic in the future, something that people dont always do. The NW is an open canvas, and I like using my paintbrush to have fun and arent afraid to let others paint on my canvas with it, as long as the picture in the end comes out great. If it doesnt, it doesnt matter because there are always more canvasses.
And I cant forget the people I consider friends on here. Daemon, Lili, Akiza, ZK, Scorps, Gobi, Nagato.., Mathias, Jinbei, etc. I met a great bunch of people through the RP over the years and while some are no longer here, it still doesnt prevent me from logging on to continue RPing with new people or talking to my current friends on here or Skype. All in all, I still find the RP highly interesting and fun, even when there are times that it isnt so fun.