I asked a French social observer why France didn't have the equivalent of an Oxford and a Cambridge by which I meant universities of great distinction and long history that were created and flourished in their own cities outside of the national capital - in university towns, in other words.
His response - France is and has always been a monarchical culture, and whereas in other countries such as the United Kingdom the universities have existed as part of civil society, in France, Paris has always been home to universities in part because they have always have been seen as a part of the power structure - whether under kings, or under Napoleon, or even under the Republic. The state has always had an interest in keeping an eye of this tool of the state, and no better place to do that than close at hand, in the capital.
Of course, the French did away with their kings over 200 years ago, and the British trot out their royals on state occasions of all sorts. Funny that.