I have done both. And am currently in admin whilst still publishing. The key to me is that admin jobs require a totally different mindset and organizational approach than academia. I am not trying to be cruel, but academia's focus on teaching and research in no way prepares you for admin work. Teaching is about interpersonal interactions and presentation of course material you are (or should be) expert at. research is about asking questions, performing analysis to know "why" (sometimes "how") something is, and then transmitting that as some sort of pure knowledge. Admin work is about doing tasks that further some type of work, or assists decision making, usually a "what". That is, admin work is about a concrete result where the theoretical aspect is not very important. The modes of communication are totally different. Academic work is based on your qualifications, networks and reputation derived through your research and publications (taken broadly). Academic work requires communications based on your position in the organization (not hugely important in academia), your specific role in how the university runs (specific in admin and quite general in academia), and your hierarchical relationships (tightly defined in admin an both tight and loose in academia - by that I mean an academic has a specific role, teach course x, and relative freedom to do whatever they want at the same time). So academics have totally different work styles and learnt behavior that lead to success. E.g. An academic gets multiple goes at a paper. An admin person gets one go at a paper. The audience for the academic paper is peers, probably sympathetic to the work. The audience for the admin paper is senior people that expect a certain template of work, done in a certain way leading to certain answers in a set timeframe.
So many academics fail because they bring academic work and communication styles to admin work. this means they are slow, inaccurate/sloppy (as defined by the admin work), and often communicate in a way that conflicts with how the place runs.This in no way indicates that academics are inferior in any way. It is simply how academics are taught to work, think and communicate.
Most admin/business people won't succeed in academia because they don't think in the right way. they don't explore the why issues. They approach things with the attitude that so long as 'that bit of work is OK then 'what's he problem'? When to an academic there is no linkage to broader theoretical frameworks, structures of empirical findings in the area and modes of communication in invisible colleges.
Hope that makes sense. Many people work well in both areas. But the logic of success is so different.