It's probably a number of different things happening to bring down the rides. On this one, somebody called in sick, and while they're trying to get someone to come in to cover that shift, the ride can't open. Another one had something break when they started it up for the day, so you can't open until you take care of it. Another had something happen with the computer, who knows.
And even if things come up a couple hours later, by then, you're on to something else, you've written those rides off for the day. Maybe you plan to come back, but maybe the time for it is gone and you don't get to it. It remains true that the time you spend running around trying to find something that you want that's open is wasted.
So yeah, it's disappointing.