Modern bikes are built yo tight tolerances for their purpose. Taking an inch curb in a mountain bike is nothing, taking it in an ultra weight optimized road bike is a different story.
Road bike chains aren't that delicate. It sounds to me like this person's chain was already old and near EOL. An inch curb on a road bike isn't that big a deal either, unless maybe it's a time-trial bike or something. The main problem with road bikes is that the wheels aren't as rugged as mountain bike wheels.
Anecdotally, on a bike ride recently, on a modern bike, hopping an inch curb snapped a chain.