Implementing Limited Job from the very start was a bad idea to begin with even if you dish out positive ideas or come up with interesting suggestions it will either make a copy of an already existing system more complicated and all of the 'Limited Job Exclusive Content' is only related to that one specific job. Just stop trying to defend the horrible system, all Limited Jobs do is cap a job at a specific level and prevent it from accessing certain duties. That is all, it doesn't provide Masked carnival or all of Blue Mage activities because in order for those to exist you need Blue Mage, not limited job.
So imagine this, Blue Mage is implemented normally like any other job and we have masked carnival, blue mage log and the achievements for morbol mount and title. We already have the raid and trials for the title and morbol achievement, we already have the dungeon and it can fit any class or party composition. As for Masked carnival it'll be the exclusive thing and yet it still doesn't rely on Limited Job as it only relies on having the Blue Mage Job. All of these content, you don't need limited job. If it was implemented normally you can still do it. Limited Job is just there to test the waters and to piss people off.
So I'll say it again Limited Job system was and still is a mistake, as it doesn't provide anything to the table other than restricting a job to be playable in all content and to make it more enjoyable. Remember Summoner's titan tanking Ramuh? What did they do? They nerfed it, no fun allowed. Its the same feeling as that, we give you Blue Mage but you won't have fun with it in the long run. We'll just use it as a hype machine to generate more sub count.