Half the fun is having something different, set up the way you want it. These bikes can be made to be just as capable as a more expensive KTM or BMW Twins with longer service intervals & better reliability. Parts availability is generally improved as well. The parts he's replacing happen to be parts that are commonly damaged in a minor accident, making a salvage bike an ideal candidate to update.
True dirt bikes? No, but awesome adventure bikes definately
Mine tips the scales at 440lbs ready to ride, 5.4 gallons of fuel, racks & engine guards & skid pans installed.
Compare that the 540lb KTM990 I had equipped the same way. The KTM got mid to high 30's mpg, my jap bike gets low 40's if I ride it like I stole it & gets high 40's if I behave.
Easy 200 mile range with less fuel on board.