I agree with the general principle being stated here, that creamies, whilst capable pilots themselves, often lack the empathy required to help students who are struggling. Creamies who have whizzed relatively easily through their own flying training cannot really be expected to understand what is required to help a student who is working really hard just to keep up.
Additionally, I happen to believe that a QFI, particularly in the military aviation environment, should have an operational tour or two behind him/her, to add some 'street cred' to the position of being a teacher. For example, it is useful to be able to tell a student that a particular process of the syllabus is important because it will be part of what they do in the "XYZ" operational job that they aspire to. It is also important to remember that military QFIs have a role in the development of their students as military personnel and (usually) as officers, so having time and knowledge of working within the overall military system means they can offer advice about the longer term career. Creamies are not well placed to do that.