I've noticed these with them
Age
Older Diesel (eww omg, it belches smoke and it's underpowered blah blah)
Ford (eww, it's a ford! yep. it exists)
a 80's vehicle. (yep, that also. much like the whole diesel is terrible and causes cancer in 3rd world alien children crap, you also have people who loath 80's vehicles. Junkyards are full of them as a example. Some deserve to rot there, others don't)
Lack of pride in domestic production. You can stitch this all together for a idea of that...
Disposable Society. Why keep something working and running well, when you can throw it out and get another? The government (state/federal) also insures this, with forced retirement (cash for clunkers, CARB diesel hysteria, etc)
I wouldn't be surprised also if many of them are just dumped in barns, on properties, in fields, abandoned in garages, etc etc like the 57 belairs, ford t-birds, old chevrolet/dodge/ford truck iron, etc. Time will tell if people actually get a idea to go dig a 85 F250 or F350 out of a field and pour a bucket of restoration cash into it like a 57 belair or corvette...