So honestly, the question is: would you want to work for a company that wants you to lie to them? or a company that wants you to grow and roots for you when you do?
I doubt most of interviewers who ask the cliche setup* do it because they hope the best for you and are glad they found the perfect match, probably they just brought it from their previous experience with job seeking, or have read them in an average HR manual.
*
- what was your biggest success in your field?
- what are your weaknesses?
- where do you see yourself in 5 years?
A long time ago a kind of douchebag asked me them while clicking checkboxes on the screen after every answer. Needless to say I had no motivation to even care to go further in the process. A few years later I've heard from girlfriends just after graduation (non-technical field), they got them on every single one of their interviews, mostly asked by HR managers with no particular work experience. The first one is exceptionally funny when the interviewee is a post-grad.
I answered this way in a recent interview (and got the job). The company owners response was "I think working with us will help you learn a lot about starting your own company." At that point I really wanted to work with them.
And to be honest: how many companies out there want someone who tells them right away that experience and money obtained during their job is only to quit on the first moment they feel it's enough to run something on their own?
Lots of people say it, few do it. It also depends on the job. A job at a small company/startup needs self starters, jack of all trades kind of people. These same people are often the ones who want to do their own thing one day.
Having never read an HR for Dummies book, and as a pure technical interviewer, I still frequently ask this question. The point is to not think of it as an adversarial question, like I'm going to mark you off for a bad answer.
It's simply to know how you want your career to proceed. Do you want to be an expert at some specific part of the programming world, an experienced generalist (consultant?), an architect, a manager or product lead, start your own startup, ... ?
This is a very important question for you and your manager to be on the same page about. It helps your manager know how to motivate you and what kinds of work will excite you to move your career forward. And it helps you evaluate via small experiences whether your vision matches up with your skills and what you actually enjoy.