Definitions on what is effort and what is rewarding are highly subjective. I mean, you could sleep your way to a promotion. It's still effort. To some, clearing savage modes are rewarding. To others, just spending an hour a day on the game is rewarding. Either way, RDM staying as it is, has no bearing on any of this. Especially to someone who admittedly has not played the job. Pushing buttons differently from someone else pushing buttons, is completely irrelevant to the discussion of complexity meeting reward. Complexity should be with the content, and the player's ability to perform in said content. Not how fast they spam the buttons on their hotbar. And I will be the last person to ask for a nerf to content.
What you see as a "simplistic" job, is actually a very fluid situational job as well as a solid DPS. A job that can jump into two other areas of utility as a stopgap when things go wrong, or even when they're just going okay. A job, that if the player puts in a little extra effort, can add complexity in its support utility. They've made a rather effective and efficient "jack of all trades, but master of none" RDM for FFXIV, provided you want to give that extra effort. The simplicity of one aspect of it, allows it to jump into a utility role on the fly.
People want to tear it down because of those extracurricular abilities, and the fact that their DPS role is too powerful for how "simple" it is. When, in fact, you have people in this very thread claiming other jobs supersede it in all aspects except raising. Raising?! Of all things... Heaven forbid a job that could possibly save a duty from failing. You have others wanting to take the utility away (cure/raise) effectively making it a fast-cast weaker version of BLM. But then nerfing the damage on top of that. When does it stop? When RDM is that loljob that nobody wants in content? That's fun! FFXI anyone?
What I find "rewarding" about this "simple job," is what I get out of it from putting in some extra effort. Jumping in there and helping out the party. RDM is only "simple" on the surface level. The complexity of the job lies with the player's ability to read the flow of battle, and know when to throw in some utility. Maybe even to keep something going long enough to pull off a win in the end.
So I see RDM as simple and fun, but at the same time complex in situations. Either way, it is very rewarding to me, from the effort I put into it while playing it.