But what you are describing is a utopia and it's also rather far-reaching. If a major show element is not working (elevator not dropping) then, yes, it makes sense for the attraction to not be operational. But if a small show element is not working, then the attraction should be open and entertaining the guests. Those first-timers, once in a lifetimers, and once every several years guests should be able to see the attraction even with minor elements missing.
That brings them back and kindles the magic. Having a closed attraction does not.
Part of the magic is the suspension of reality. Animals can't dance and sing (or at least they shouldn't!) in real life. If I'm on a log riding through Splash Mountain or a boat in Pirates and all the sudden we float past a cluster of frozen animatronics, I'm snapped back into reality. Think of how jarring it is when a CM has to come over a loudspeaker because someone inside the attraction is being an idiot. How lame would it be if you're on ToT and the doors open and the room is just dark? What would RnRC be without the soundtrack?
Personally, I'd rather them go down, reset the computer or whatever, then start taking guests again. Many of these things are quick fixes (within an hour, usually much less). I may be wrong, but I believe on DLR's Space Mountain v.2.0 (the first attempt at sound), if the sound went out on one of the trains, they could send the vehicle through empty and by the time it reached the station again the onboard computer would have had enough time to reset and be functioning again. In that instance you loose 12 people off your hour's throughput? Big deal. In others, maybe the line stops moving for 15-20 minutes. Again, big deal. What's a park hopper cost these days? Over $80, right? That's a lot of money. I think it's reasonable to expect to see the attractions as they were meant to be seen.
The problems with Mansion sound so acute, you have to wonder if it looks this bad to the public, what do the systems look like that we can't see? I'm not suggesting they're running an unsafe attraction, but the situation does beg the question.
I'll also add that it's not just the hard-core fans that notice this stuff. A guy from my office took his family down to WDW last month. He hadn't been since he was a kid. For the attractions at MK that are still there from when he last visited decades ago, he said it was like a time capsol. They were exactly the same - and felt dated/worn out. This is a dude who isn't in to details, and
he noticed it. He added that having rented a suite at the Poly, when you're spending that much money you pretty much expect close to perfection, and aspects of the trip were far from that. They had fun, but aren't dying to go back. So, these things do take a toll over time.