What do you think was going to happen when Kaddafy died or for some reason stepped down?
People talk about “stable dictatorships” but it is a fiction. Dictatorships are always inherently unstable and on the brink of collapse. The efforts Kaddafy put towards keeping himself in power are the same efforts which hamper the development of a stable nation. The same ones which create the condition they have now. There was no kind of succession, rampant ethnic division/discrimination, and a military made up of nepotistic sycophants (whose previous battle experience was getting their butts kicked by Chadians in Toyota pickups See “Toyota War” for details).
Blaming intervention for the current conditions ignores the rot underneath the regime that was festering for decades.