It's a lot more convenient to just fill up one tank with diesel than it is to jockey around to also fill up with propane. Diesel is everywhere. While propane is certainly around, sometimes you have to look a little harder for it - make a second stop some place. Mine came with a diesel generator, that's what I prefer and it was one less detail to sort through. Also, after being around propane forklift engines for years, I find it a lot easier to find a diesel shop that can work on diesel engines than a good shop that can work on propane engines.
Bill