I get where you're coming from, but the fairness of it isn't really SE's problem. They don't officially condone the use of parsers despite that fact that a lot of people openly use them. It comes down to PC's being ABLE to run third-party parsers whereas consoles can't. It would be unfair if they added an in-game parser but only gave it to PC players. That's unfair. As it is, it's merely a difference in technology design between a PC and a console.
That being said I've always been somewhere in the middle on this issue. If they added an in-game parser then I would use it to perfect my rotation even though I feel like I've already mastered my main class which is NIN. It would certainly help me perfect alt classes like MCH and DRK. Then again I'm perfectly fine if they never add one because I enjoy being able to overcome the challenge of learning a class based on my own abilities to problem solve and think critically about my toolkit.
Bottom line is that there is far too big of a stigma around parsers and the potential for harassment for SE to condone an in-game parser. At least for now.