How many million mile gas V8 engines do you know of ? I know several Volvo 2.1 and 2.3 redblock, and 2.5 whiteblock at, or near 1.000.000 kilometers. And in diesels, Mercedes OM 616, OM 617, OM 605 OM 606 and VW 2.5 TDI outrun the tacho.
The bad mouthing of V6 in full size cars and trucks originates from the same era as when diesel got a bad name in trucks: during the oil crisis Oldsmobile converted a gas engine to diesel, which couldnt handle the twice as high piston pressure. (Mercedes had the 300D turbo of also 120hp but from 3 liter, which ran a million km) and in the same era, salesmen that ran a lot of miles, started buying the cheap-*** economy V6 engine with a much lower designed lifespan, for fuel economy.
And then, lets get real: for "real truck work" you dont get a grocery getter half ton with comfortable suspension, for "real truck work" with a trailer you'd need a 3/4 ton with "real truck" rear springs....