That’s just their role for that particular story. Per Walt, the “real” Mickey and Minnie are married, they just sometime play an unmarried couple when the plot calls for it.
I have been in Disneyland Paris a couple of times. The last time was just a few weeks ago. I recognize exactly where that couple was. It wasn’t just a briefly empty area; they clearly wanted a semi-open space with the picturesque background, so they would have had to climb over a thigh-high fence unambiguously marking the area off limits to get there.
I guess Disney has to make apologetic noises for PR purposes, but the couple were absolutely in the wrong and the employee was correct to interrupt and kick them out.
But Your Honor, I didn’t say Minnie was CRAZY, I said she’s fucking Goofy!
No. It doesn’t. They are no more special than every other visitor at the park and they have to follow the same rules. “Because I want to propose” isn’t an excuse.
The presence of pyrotechnics does change things. If there were pyrotechnics in that area, then the time to get them off the stage isn’t “in 30 seconds, once he’s finished asking and she’s answered”, it’s “RIGHT NOW, if not sooner”.
On the other hand, by the same token, the presence of pyrotechnics also means that the barrier should have been more substantial than a thigh-high fence. That might be enough for safety for a private event where all of the audience are known, but it’s not enough for a public place full of who-knows-what idiots.
I’ve had some limited behind-the-scenes glimpses at a theme park (a dolphin show type of park – several, actually). They are very serious about people-control. They have to be. Let one person climb a fence, or try to pet the tiger, and you’ll instantly have a stampede of the whole crowd trying to do the same. I’ve seen it happen. They need to be really strict about stuff like that.