Planes, Trains & Automobiles is one of the best examples of this formula. Dinner For Schmucks is so-so, but can't hold a candle to the aforementioned classic.
The thing about Planes, Trains and Automobiles is that John Candy is genuinely a sweet and good person, and the annoying part really only comes into play because of personality conflict - and the life ruining isn't his fault at all. For that reason, it's easily among the best of this type of film.
Anger Management is one of the worst of this sort. Hate that film.
Well, all semantics aside, Steve Carrell's character from Dinner for Schmucks that started the thread is also a genuinely sweet and good person. I think that's the point.
But yes, Candy's character in
Trains is not directly responsible for ALL of the havoc in Martin's character's situation, but he does contribute, like the mixing up of credit cards and unintentionally setting fire to the rental car that the latter is financially responsible for. So he definately causes some havoc.