Well it depends on where interests are, I work with developers who are not creative, everything they do is logical and struggle when they design. Me as a designer I don't like development, I do like front end development were you can see code coming to life.
Some people are specialists, some are multi...um...ists. It's certainly possible, and I think employers seem to be looking for Jack-Of-All-Trades "designers" these days. But this kind of work does have a side to it that encourages specialisation. I, for example, can do the odd bit of graphic design, as well as basic video editing, but my main thing is illustration, and I tend not to market myself as anything other than an illustrator (no matter how many logo jobs I seem to do...) People only have so much time and energy to devote to improving themselves. Do you want to hire someone who dabbles across multiple disciplines or do you want number of specialists working together?
My speciality is 3D design.... I can do graphic design (had to do this before I could study at uni) and even basic web but I don't sell it as a service (from what I've seen locally I'm better than some that do sell it...), I'm not exactly fast with web design lol
I'd never do illustration, I'm not trained in that area and to be honest it would likely just annoy me... I'd call on someone like Jim (or others depending on style) who specialises in that line of work.
What I do think is useful is that anyone working in a field that requires another person, say a web designer who can't actually do the backend coding, should at least have an understading of what can be done even if they can't do it themselves.
That makes sense Levi. I did 3D modelling as part of my course at uni, and like you with illustration, I find it annoying and even ignoring how out of practice I am with it I'd be pretty slow. Good to understand the basic principles though in case you need to discuss it with someone i.e. the client or someone you outsource that part of a job to.
Personally, I'd have to say yes since I was a graphic designer for 10 years, then switched career to be a software developer. I'm probably not the greatest in the world at either, but I'm more than competent at both. Is that common? No, I don't think it is - but maybe not as rare as you might think. In my experience, the most successful developers are usually also pretty creative people, and the most successful designers are usually also pretty logical.