Honestly, your career switcher story may have been what cost you the admit. I saw from your profile that you said you were interested in finance / VC post-MBA. Career switchers can make AdComs wary, especially when the end goal is something "sexy" like VC or PE and there's no clearly defined path as to why the applicant is looking to go into that field or what attributes they have that would lead there. AdComs are realists and they make you write those career goals essays because they're looking for people who are going to be successful alumni. VC is extremely hard to break into, especially if you have no past experience, even if you're coming from HSW. Basically the career center says that if you don't have a finance background it is a very, very long shot. Admissions may have seen your IT management past and career goals of VC and thought it was too disconnected.
My advice would be to better connect the story (VC is my passion because of X, you can see this because of XYZ things I've done in the past, and here's how I plan to break into the industry). It's fine to have VC as a long-term goal, but be realistic and create an intermediate goal if it makes sense (first to X company/industry to increase my skills and then to VC). Conversely, you could change your story to something that better fits your background / personal history (i.e., if you've always done pro-bono IT consulting as a extracurricular, you could say that your end goal is to start an IT consulting firm for a specific market segment because it marries your professional experience and personal passions). Now, this doesn't mean you need to give up on your VC dreams - but for the admit you may need to better tailor your story for your background. 80% of applicants end of changing what they want to do anyways and there's not going to be someone cross-referencing your application when you show up at VC recruiting events on campus.
Of course, this is all pure speculation, there's 1001 things that could have led to your results, but I know that story and career goals are really important. Just my $0.02.