Disneyland Paris has a lot of critics, who have never actually stepped into the park. You see it on themeparkinsider & elsewhere when a Disneyland Paris story is shared & people pile in with their thoughts - it’s painfully obvious they’ve not visited.
I understand some of the hate, as they view the park as taking investment from their beloved USA destinations.
The resort itself is close to Universal Orlando for enjoyment, and significantly less stressful than Disneyland & especially WDW to visit. I feel it takes the easy going aspect of Universal & fuses it into a Disney resort, and it just works. No mass planning required, which is a big tick for what is effectively a place to escape the perils of the modern world (take note Disney in the USA!)
The entertainment at Disneyland Paris is better than any single resort in Florida, They make genuine effort at seasonal events unlike WDW who have rehashed the same expensive, stale parties for years and years & have a park filled with shows that have been there decades. Or Universal Orlando, with its…4? empty theatres.
There are however issues & the place is several, easy but costly fixes, to being unbeatable. A Hagrids style coaster, a few modern dark rides, a fantasyland expansion. As I say, expensive, but the foundations are well & truly there.
Anyone who hasn’t experienced parks outside the USA should venture to Europe if able to do so. Parks like Efteling, Alton Towers, Phantasialand, Port Aventura, Disneyland Paris, & Europa Park have some great highlights.
In terms of the location being a mistake, I think being so close to Paris has advantages. I think the climate where Port Aventura is (an hour from Barcelona) would have added a different kind of appeal to tourists, but also a I doubt the same infrastructure was in place.