Disneyland Paris has problems and issues which the California and Florida parks do not.
The main historical problems stem from the fact that Disneyland Paris is not and never has been wholly owned by the Disney corporation. This has impacted everything from maintenance and upkeep budgets, to staffing budgets, to entertainment budgets and so much more.
The other issues which Disneyland Paris face is cultural and social behaviours and expectations. Disney does not equal America. Disneyland Paris is Frenchified Disney. Everything from the behaviour and expectations of guests to behaviour of staff reflect the location of the park, ie France and Central Europe. There are huge cultural differences between society norms in America and society norms in Europe. The Disney Parks are a reflection of the country and society where they are located. Therefore the California and Florida parks reflect the culture and social norms of America.