Personally, I think the "theme park" mentality means we cannot have really difficult lower level content.

Things are so centered around Duty Finder and "hop in, hop out" random parties, so the content needs to be clearable by uncoordinated groups where people just play at a minimum level of competence. With no social connection/obligation to the people you play with, there is no need to stick it out, and parties will simply disband after a wipe or two.

Fortunately or unfortunately, that is what the game is now and there is probably no going back to rejig lower level content. The only challenge is endgame.