Rien ne dure comme le provisoire
From dKosopedia
Rien ne dure comme le provisoire is a French aphorism that may be translated as "Nothing lasts like the temporary" and which means that temporary fixes or compromises have an unfortunate habit of becoming lasting institutions. Inferior institutions or rules often survive because the cost of changing them is too high for the expected benefit to any particular political agent. This problem is related to the market failure known as system effects.