If you create a military starbase and use a soldier citizen does that citizen give a bonus? If you build a culture starbase how about an entertainer citizen to give a bonus?
If not, I do think that using the "correct" citizen for a starbase should give a bonus for said starbase.
Since citizens aren't locked into a certain occupation, this would be pointless. A citizen becomes an engineer by virtue of being put on a Constructor. Just put your criminals or rabble-rousers on constructors and colony ships destined for non-core worlds and be done with it.
The issue I have is that citizens of a particular race aren't diverse enough for it to be worth the effort to pick and choose occupations. You're always going to want to focus them all on one thing (farmer, worker, etc.) so the granularity is unnecessary. I actually think citizens should only have traits and that leaders should have both traits and stats. It's really the traits that matter for citizens. Consider when you have citizens of another race on your planet. You're always going to want Torians to be scientists, Yor to be workers, and Baratak Grove to be farmers because they have a racial trait that biases them towards those things.