I think he means it will have less wear because the engine will be hot as 90% of damage to an engine is done in first 5mins until it reaches temperature.
I still don't buy it. 5000 miles of 2 mile trips is only 2500 journeys, some of which might not even last 5mins. 500,000 miles of 100 mile trips is 5000 journeys. In all likelihood, the car with 500k on the clock will have spent more time being driven at low temperature than the car with 5k on the clock. And that is really taking things to extremes, assuming the cars never do longer than 2 miles or less than 100 respectively which is basically never going to happen.