Hi, Think about it this way-
Past + MBA = Short Term + Long term goals
Your reasons for doing an MBA should logically come from "How you have identified various personal and professional handicaps in the last 15 to 18 months. The school should be able to assess the incremental value and MBA program will bring to your professional career. If you tell them that you are keen on doing something different, you should have a strong reason for "WHY IS MBA THE FIRST STEP ?" I mean- Why is MBA a major roadblock between what you are doing right now and what you want to accomplish in the short term?
They would want to see - What actions have you taken in the past to get closer to your FUTURE? It is not a very convincing argument if you tell them that - YOU have NOT DONE A THING- and only an MBA will help you ROCK in the alternative career.
Stay within the risk appetite of the admissions committee members.