Every ride breaks down once in a while and sometimes needs to be evacuated. This has been the case for both Riverboats and the trains. As Vegitabeta says, though, the level of complexity isn't the same and thus some rides are less likely to break down than others.
Also, an important aspect of those specific rides is that they're fully controlled by Cast Members, while roller coasters such as BTM are managed by use of computer systems to a large extent. A computer will shut down a ride as soon as it senses the slightest risk of a problem while human operators can assess a situation and react accordingly (which is not to say that they're taking any risks, obviously)...