There seems to be a huge misconception of what casual actually means. There is no reason not to try all that the game has to offer, including EX, savage, and ultimates. Anything can be cleared if you are willing to invest enough time into doing so. The only factor that sets apart a casual to a hardcore player is the amount of time they are willing to invest.
Plenty of groups out there that tackle "hardcore" content in a casual manner. Plenty of groups out there that are comprised of very new, and with a very basic role understanding of what "hard" content means. The only thing that is missing is the willingness to attempt it.
While varied content is a good thing, those challenges are part of the game's diversity.