interesting stats from the Orlando Sentinel:
The Frozen water boat ride, open since June 2016, has generated more calls for evacuations to Disney's fire department than any other attraction over the past two years. In fact, Frozen accounts for 20 percent of all ride evacuation calls made to Disney's own first-responders, Reedy Creek firefighters.
Out of more than 550 ride evacuation calls, 113 were for Frozen, according to data provided by Reedy Creek.
Two other longtime attractions open since the 1970s came next on the list, with Pirates of the Caribbean, another water ride, having 72 evacuations and Space Mountain with 64
https://disneyworld.disney.go.com/dining/early-morning-magic-toy-story-land/
We've ridden Frozen maybe 3 times and have never experienced a break down. Have you? We've certainly been stuck on other rides more often, and physically evacuated from maybe 3-4 rides over 15 years.
I hear, and the article mentions, that water rides are generally more challenging to maintain.