Yes because we all know this terribly broken game we are now playing is how it will stay forever, they planned the job system more around ARR, ARR could very well have things jobs have a hard time soloing but classes are a lot more efficiant.
Also you may hardly have to solo, but there are people who prefer to solo than party, think of the BST from FFXI, if you enjoyed solo play you leveled it, I would ask people "why should I level BST" I would get told "its the best solo job" so obviously people choose to solo over party when they can, this is the point of it all and thinking ahead to ARR.
