Should we be limited to only one craft class?

[Darium]

Just to clarify, you are talking about the job system right?

I'm pretty sure you are so I'll join right in and say... They already are.

Only a Gladiator can be a Paladin. (Have access to Paladin skills and traits etc)

Yes, but that same person can level MRD and open their job. That is where the difference begins. If "you" (that is the impersonal you) can level MRD & GLA and open their jobs, why should I not be able to level ALC & TAN and get their "mastery"?