That is a very naive point of view. Governments don't work like Yelp or Hacker News or something. There are people that represent or have the support of powerful lobbies which make things change. In this case, the taxi union. The article even talks about this move being in response to threats by the taxis. "With Paris taxis threatening to create traffic chaos on Monday with a go-slow action to protest the ride-booking company, an Interior Ministry spokesman said that Uber’s low-cost service, UberPop, would be prohibited in France as of Jan. 1."