You also get the double punch of WDW expanding so massively in the 90s and the USA becoming cheaper and cheaper for tourists to visit, that for those in search of a Disney fix the price difference between Paris and Orlando became narrower, which didn't help DLP's quest to get guests who wanted to spend a week or more at Disney parks. Many people said 'for not much more, we could go to Florida', while nobody, when offered the choice said 'I'd much rather go to DLP than WDW!'.
I used to work for a company in the UK and asked them about Disneyland Paris. Many thought it was too expensive and, if you're going to do Disney and spend all of that money, then you may as well do it right and head to Florida where everything is.
They saw a lot more value in traveling to Florida for 4 parks over, what sounds like, 1.5 parks in Paris. Also, USF/IOA were factors in their decision with them being just down the road.
I read up on the problems of Disneyland Paris a year or two back and, outside of them kind of competing with Florida, there were a few things that stuck out:
- employees were generally rude and unhelpful
- management has it's own share of problems.
- They made everything really ornate when they built the place but, with that ornateness, comes maintenance which they couldn't afford and then it just got worse from there.
I remember reading one of the comments on DLP, from a British person, and they basically wanted to go to Florida, not only for all of the other reasons above, but also because the people in Florida treated you like a guest instead of a pest.
I've never been to DLP so I don't have any first-hand experience.