How would you solve the boring "damage rotation" of the healers?

[TheDustyOne]

Well yes obviously the barrier to entry is not a reference to being able to play the job but play it effectively. Ie to master it.

I think you're getting them mixed up; a low barrier to entry means someone can pick up the job and play it effectively, but mastering it involves going to great lengths to optimize it, not merely doing well with it.

BLM as you pointed out isn't actually that hard to understand at it's core, however, it has small nuances and techniques that you don't need to touch to be able to play it effectively; transpose-lines comes to mind. A new BLM player can get by with simply knowing to use Fire III when they finish their Umbral Ice phase and can get by with using their Firestarter proc only when they need to move, an experienced BLM may understand how strong it is to instead save Firestarter so they can Transpose from Umbral Ice and get a slight bonus from switching back to Astral Fire. It's a job that is fairly simple, but absolutely difficult to master, and satisfying to play well.

A BLM main could probably better explain how to best use Transpose, I've only had a very cursory glance at it and I don't use it in my own BLM gameplay, I stick to a standard rotation myself.

SMN on the other hand has very little to master beyond its basic rotation, the most you need to learn is when not to use Ifrit and Garuda Slipstream. It's simple to play, but mastery occurs very quickly, and ends up being pretty unsatisfying after a while.

Being easy to learn and hard to master is the mark of good game design, having jobs that are hard to get into simply because they're hard to get into doesn't make the design good. Some ideas and concepts for how a job might play may necessitate a higher skill floor, but ideally should still have some fallback options to avoid punishing bad play excessively.