I think this system is actually more successful than the devs give it credit for. The issues with SCH/SMN stemmed from the old attribute system and the INT stat being the source of damage for both SMN and SCH. As it is right now, it actually isn't that bad of a concept. It was just implemented incorrectly. I don't play SMN, but one of the issues I have and many others have are the lack of true summons, which has nothing to do with the ACN base class. SCH is currently flying high amongst our healers. There are no issues I am currently aware of with SMN as a result of sharing the starting class with SCH, but someone can feel free to enlighten me.

I believe the devs wanting to go away from classes has more to do with where they want to go with the game than the system being fundamentally flawed. I find it to be really cool to start off in a weaker discipline that grows into a true job, which was a big reason why I opposed RDM and SAM starting at 50. I found this to be far more lazy than practical.