I'd wager to guess it is usually due to guest stupidity, not an actual breakdown.My 6-yo daughter calls Splash Mountain (the one in DL), "the ride that breaks down a lot". We've been evacuated off the ride and have left the line multiple times because of extended breakdowns. It would be nice if the ride was more reliable but it's nothing to be concerned about.
It's all the same to a 6-year-old.I'd wager to guess it is usually due to guest stupidity, not an actual breakdown.