Close.
Keeping in with the amusement park example:
Some rides have height requirements.
Some rides have age requirements.
Some games require more skill than others.
By that example, the current model works just fine, as there is something for everyone, but not everything is for everyone, which is as it should be.
A kid who is too short to ride the Top Thrill Dragster (A casual who can't fight the real Ifrit) shouldn't complain that they need to make an identical ride scaled to their height. (As a casual player shouldn't expect an endgame fight to be scaled to them.)
Casual players shouldn't be able to do the content, at all, if they can't put the time in to do it at it's appropriate level and difficulty. There is still plenty of other things for Casuals to do because, as we agree, it's an amusement park.