While anecdotal, I believe much of the mid size crowd does look at their vehicles and what the payload/capability ratings are in the rest of the world. Many vehicles throughout Europe are used to tow trailers. Seeing a VW or Mercedes station wagon towing a travel trailer (or horse trailer) in Europe is not uncommon. A mid size truck for many in Europe does duties that US people would only ever use a HD truck. So a mid size truck is a very capable machine.
The big difference comes as many have noted from the regulatory restrictions and how the vehicles "can" be operated. In the US everyone wants to pull their travel trailer or drive their overloaded Tacoma at 75+ mph. Crazy!!!! So you have to now adjust the vehicles legal capability.
In Europe many countries restrict personal vehicles towing not only to a max speed (regardless of a higher road speed limit) but even lower limits depending on the type of road. If you are driving in an urban area it is usually limited to 30 mph and highways 50-60 mph (country dependant). I believe Australia is similar but I have no experience there.
This adjustment I believe allows other countries to rate these mid size vehicles higher and the US lower. The view from some midsize owners is that if it can do "x" in Europe or Australia then it can it is just US nanny state that keeps them from having fun. In reality the other limitations that these governments impose (speed, different following distances, etc) allow them more freedom in the capacity of their vehicles. So it is a give and take. However, those US owners want their Tacoma to haul the same as their worldwide brethren while still doing 75+ on the highway and manage crazy US urban driving.
