The biggest problem for the member of the public is, how do you (they) differentiate between a "stoppage" and a "break down".
Do you define a stoppage as something that doesn't require an evacuation? what about if you are stopped for over an hour before they restart the ride? If not an evacuation, do you then consider time to be the factor? if you are stopped for more than a few minutes, do you consider that a stoppage and not a break down? In reality its far more complex than that.
The average member of the public probably doesn't know enough, or care enough about the operational side of things to be able to tell the difference. That and it's not exactly like our parks tell everybody the actual reasons for things happening. So it's not like it becomes common knowledge/practice anyway. So anytime they ride they probably expect they aren't going to be stuck/stranded/stopped at all, even if it is only a few minutes. So everything is going to simply seem like the ride has broken down.
Education is a problem too, because you are only going to be able to educate those people who go looking for the information, it's never going to become a mainstream media interest that causes every person to view/read anything published. Again, the majority probably aren't all that interested about how they work outside of they go fast or turn upside down. Even with some really clever marketing, the number of people you actually reach within your target audience is probably so low that it's viewed as a waste of money.
The main problem probably lies in that all parks tightly control what is said/released to the public/media. From the lack of simple explanations when incidents occur, right down to a simple warning about stopping during use. So it's difficult for every day stoppages and malfunctions to actually become every day knowledge for your guests. It would take a vastly different approach (and many years) for a simple ride fault and a planned, walk off evacuation, to become as normal as getting a flat tyre or having your battery fail and having to call RACQ.
No doubt there is a level of fear involved there; acknowledging something has gone wrong and fearing being persecuted or indeed sued, plus you have the very real chance of incorrectly reporting an issue until it is fully known (which may take days/weeks, etc), so I can see why parks want to stay tight lipped when it comes to issues like this.
If you opened up your park for filming maybe short 5-8 minutes segments, explaining each of your rides (i.e. 1 segment for each ride), including details on when it was built, how often (and how involved) they are closed for maintenance, how often they are checked and how it's safety functions work to protect you, maybe even simulating a ride fault that causes a stoppage? along with its key facts like height, speed, forces, etc (which most general people find kind of interesting); then made it available through various media channels, it could possibly be marketed as a behind the scenes access sort of deal anyone can access (without having to pay a large sum of money). Maybe have a host and the same engineer involved in each segment so people kind of relate to the same people each time?
I wonder if all this change in attitude simply starts with additional warnings, perhaps something like, "While all checks and maintenance is thoroughly performed, amusement rides are complex pieces of machinery and may stop running without notice". Coupled with having a prepared, informed response for operational staff when even simple ride stoppages happen, maybe it would start to make it seem like nobody has anything to hide, and it's just a part of normal park operations that sometimes things will stop, but there are competent people behind the scenes that will be working to keep everything safe and get things going again.