I agree with the OP that the system available in FFXIV needs to offer at least some choice in specialization for each job. Right now World of Warcraft actually beats this game hands down in their class system because even though you can't play every job on a single character, each "job" offers three different play styles within that job and players can freely switch between two of those styles. This allows for hybrid classes to actually fill two different roles, damage dealers can experiment with different kinds of play, etc. Heck, even though we can play every class on the same character in FFXIV, it's really no different from starting a new character in WoW and leveling that character up, only they have a seperate inventory so they don't run into the issues we have with the FFXIV inventory.

I mean, we could have Dark knights that could be a DPS or a Tank if we used that idea of offering multiple paths. Or a Bard that could specialize in healing or be a sniping savant.