I have to add my thoughts. I am a relatively new carrier flier. I find the event to be challenging and fun. Sure it takes a lot of work but this is a hobby and that is part of the fun. In my location we have had a renewall of carrier flying over the past year or so. At our field of about 15 to 20 regular control line fliers there are at least 7 or 8 that have carrier models. We have a lots of fun with them. Some are not even new models but oldies that have been updated. There is one flier that uses a Thunder Tiger 36 and gets some very good results ( in excess of 340 points). He proves you don't have to have a Nelson or some other exotic motor to do well. Its being able to trim and fly the plane well that makes it work. Just like any other event.
As far as models, Eric Conely has built a ME 109, and a Corsair that he flies extremely well. I have a Dehaviland Vampire that can compete with the MO-1s. I also have plans for a Crusader that should work well too. You do not have to stick with MO-1s to be competitive.
I have recently built and flown an electric carrier plane that works very well. There are others in the midwest also working on E Skyray carrier. For many reasons electrics are the future of many forms of aircraft modeling and also a new an interesting experiment. We have only scratched the surface of this form of carrier flying.
As far as being maxed out, I don't think so. New records can be set and there are people working toward that. Look at speed records, they don't just keep changing every year either.
What's the point? I could say the same about stunt or combat or speed or racing too. Its all in the opinion of the observer. If you don't find it a challenge and interesting then do something else. Don't just bash those of us who do enjoy it.
Yes, there are fewer entries than in years past but look at some of the other control line "specialties" the same can be said for them. CL is not as attractive as RC for many of the new modelers. There are no ARFs or foamies for carrier, you have to build your own plane. Then you have to understand it well enough to make it work. What a concept, you have to be a modeler! There are fewer places left where you can fly CL so that reduces the chances of someone even seeing CL happening.
All in all some of us still enjoy carrier and do our best to keep it alive.