Does the general manager need an experience? And do we consider IT Manager position a technical job or does it relate more to policy and planning?

Definitely, experience is an ansolute necessity to have a successful manager of any sort, whether General Manager, IT Manager, HR Manager, Finance Manager or what so ever ...

Experience is no substitute to knowledge and knowledge is no substitute to experience.  Life and experience may teach you things that they don't teach at Harvard or MIT.   In my view, we have knowledge, experience, attitude, discipline, maturity and wisdom as desired attributes in any effective/successful manager in any discipline.   Knowledge includes the subject matter knowledge of course,  so that an IT manager would know IT, Finance manager would know finance and so on so forth, but they do not need to be top-notch experts in these fields.  Simply because their main job is to manage and to be an expert in any of these fields !!