You have to factor in after so long with having someone like Moggi who got out of control and who they really couldnt have in check, they just took people, they thought would be ok enough to steer the club (plus prolly not having alot of choices and just going with two clutz within the club, and a frenchy with an impressive CV), but most importantly would be much easier to control. And would have little to no risk of going outside the reservation to say the least (Gigli for example just a former fiat office rat who i just a the face out, easy to control, think his contract is running out too).
And also, an important point is they wanted totally new people out of PR reasons, because it was such a paranoia in Calciopoli that anyone working in italian football was getting quite the skeptic treatment of being semi-dirty by association just for working in that football "inviroment". So they probably wanted just a clean slate just for appearance sake (their catch phrase was the new Juve being propogated), and not risk getting veterans of calcio because of not being perceived to get the same old, even if its the most honest person in the world and one who would be great for us (it was a total witch hunt that just by working in this bussiness you got grilled, Lippi was frigging defamed, any innocent player was threatend to be sued etc). Plus no offence, but even if we are a biggiest Italian club, I dont think the most competent and rated people were queuing up to work for us after that scandal.
I really dont know hardly much if any of the direct details (was too busy being devastated) so scusi for the rant , for example I dont even know who Montezemulo or whatever is. But besides thinking the current owners not caring for the club much IMO (except in pragmatic way) to want to invest, I just think the above may be reasons they acted upon with. They themselves arent probably that competent (footballing wise, financially astute probably, even if Fiat isnt doing that great with the current generation), and there is alot of scheming we dont know about. But mainly think they were too busy and insanely pressured to doing damage control, and hence getting totally new non football people being vital for them to restart, not just in a concrete way, but was probably important for them to have a clean slate for appearance sakes (the bussiness world dies and lives with reputation, and ours was totally tanked).