Just because they're smart businessmen doesn't mean they're making a smart financial decision. They probably make enough money as it is so they can justify spending the extra cash to always have a newer vehicle. It's the guys that are closer to paycheck to paycheck that are screwing themselves.
No one in this society wants to save their money and buy their own things anymore. A new car should only be for people that make a lot of money and can afford it. They have it set up so anyone can buy a new car and sure enough pretty much everyone owns a new car these days. The only problem is that it straps you financially for 5-6 years so most people are paycheck to paycheck because of it. Then once they get close to paying it off or get it paid off, they immediately trade it in for something new and repeat the cycle of stupidity over again. Unless you're well off financially, buying a new car is a suckers move.
That is essentially what I've said in this thread. THough, I agree with sturg or whoever in that it's not as big of a difference as people make it seem.