It doesn't matter if you can play 1 job or all jobs.

I play always more races in every game, also in FFXI and FXIV and will also in FFXIV ARR.

In mmorpgs that have only 1 job for each character you just make alts, for the sake of doing other jobs.
I really don't see the difference, in changing jobs on the fly, or just change to an alt.

If you do your job good people remember you. How you act is how people remember you, having 1 job or many doesn't change that.

You still can decide to play mostly 1 job. You probably play a few more for skills, but after you have them you probably focus on the job you like the most, because that is probably the job you are best with.