Let's stop catering to the huge portion of the subscriber base who belong to the 'casual' classification, and instead focus entirely on endgame raiding and preparing people for endgame raiding. That worked out spectacularly for Wildstar, after all.

On a more serious note, I don't think that gating off Ex/Savage behind some sort of test of ability within a given role would be unreasonable. They did this in The Secret World, and I don't remember them being a big to-do about it. As a casual player myself, I attempted the boss fight required for high-end content in The Secret World, got thrashed, and promptly decided "well, I guess I'm not ready (yet)."

Similarly, I have done a few Ex fights in XIV, and didn't like being carried so much, so I decided that this content wasn't for me (I haven't even tried Savage yet, and doubt I ever will). I'm happy with doing normal raids, dungeons, and 24-mans, and have worked fairly hard on getting better at tacking that sort of content—e.g. through watching dungeon/job/raid videos on YouTube, practicing rotations on dummies, reading tool tips etc.

But I am unwilling to wade too deep into the technical minutiae of jobs, as it runs counter to how my brain works, and how I approach games: e.g., intuitively. For a person like me, an in-game parser isn't going to work, and if you spit back my numbers at me in a dungeon I'm not going to pay that any heed, either. If, on the other hand, you politely call me out on something sub-optimal I'm doing, then I'm always going to be amenable to changing it up.

All of that being said, I do wish the game did a better job of explaining mechanics, job actions, etc. in the game itself. External resources are fine, and they are probably necessary for high-end content or working out the niftiest ways of 'breaking' content, but for the people who just want to use whatever time they can spare for gaming to enjoy the game itself, it would be handy if, say, job quest lines actually did more to teach you how to play your job, in addition to telling a story.