Graphicly making a WHOLE game is immense. Normaly you would have loads of graphics artists in one house of which would share the load.
(My knowledge from here is sketchy, but I think im on the right track)
If we were to take LFS as an example, each car in the game would of been made by one person. So, 24cars would be done by 24 people, 12 by 12 etc whatever the number. Each track would also most likly be done by one person, or even sections done by seperate people, but all working to a strict limit. So, one person would make BL straight, someone else the wee bridge, someone else the next corner and so on. It all depends where / what the company does.
I can make a model of a car in hours... BUT, thats sloppy work that has to be chamfered and turbosmoothed to look even slighly decent. Recently, I started to make low-ish poly cars for another game and they take me weeks or more. You gotta model, make textures and uvw unwraping, smoothing groups have to be perfect or it's look shite then tested ingame. From there touchups would be made and the process might have to be re-done...
But, a whole game, graphicly made by one man, is a big bloody job! And I dont think anyone can fault it... So give the man some slack.