It does not compensate developers for working on mundane projects.
It does. That's not the sole reason why consultants make more, but that's a factor.
If you're a full-time employee, you expect your health insurance, HR, work supplies, 401k, office space, finding of work, and your career growth and promotion planning to be taken care of, and you're likely to leave if you're not getting it. If you're a consultant, you're taking on those responsibilities for yourself. That's a big part of why you charge a higher hourly rate. It's to include buying your own health insurance and having to manage your own career with no expectation that the people giving you work give a damn about your vector.
That's not to say that typical middle managers or companies actually care about the careers of most people under them, but they at least pretend to, and some actually do. It's part of the social contract that exists for an employee and not for a consultant. Of course, after being an employee for a while and seeing that part of the social contract ignored, many people decide that the job is too important not to do themselves and start managing their own careers... and some become consultants.
Most consulting engineers (in IT) work for body shops. The pay is poor, the work is boring, the hours long, the turnover high, and the output mediocre at best.
A well managed internal team could do the work at 1/3rd the cost but the work is rarely a core part of the business and no executive wants to deal with the internal headaches and risk associated with the work when it won't get them anywhere politically.
The "contracting" world is much more like what michaelochurch described. And to be fair there are a large number of individual contractors working at large firms for great daily rates (think $1000/day on the lower end) for which what he is saying is true.
You'd probably know more about that world. In your opinion, are these consultants more like corporate employees (in terms of demanding managerial investment in their careers, and slacking or leaving if they don't get it) or are they more like independent consultants (who'll do a nasty project if the hourly rate is high)?
I'm in that world right now. Most here are like corporate employees, with a few exceptions. In most cases people _will_ do a nasty project to help the company, because in the past the company has turned away the nasty projects even when they looked profitable, because they were more interested in slower growth of interesting work than quick money from boring work. When that boring work becomes necessary, people are prepared to do it on the assumption that there'll be interesting stuff around the corner. So, here at least, the trust flows both ways, and that's a great thing. (edit: since I'm replying to you Michael, it's probably worth stating that in your terminology I'm currently working in a "guild" environment, and that's rare enough that my experience is probably the exception not the norm.)
It does. That's not the sole reason why consultants make more, but that's a factor.
If you're a full-time employee, you expect your health insurance, HR, work supplies, 401k, office space, finding of work, and your career growth and promotion planning to be taken care of, and you're likely to leave if you're not getting it. If you're a consultant, you're taking on those responsibilities for yourself. That's a big part of why you charge a higher hourly rate. It's to include buying your own health insurance and having to manage your own career with no expectation that the people giving you work give a damn about your vector.
That's not to say that typical middle managers or companies actually care about the careers of most people under them, but they at least pretend to, and some actually do. It's part of the social contract that exists for an employee and not for a consultant. Of course, after being an employee for a while and seeing that part of the social contract ignored, many people decide that the job is too important not to do themselves and start managing their own careers... and some become consultants.