Do you have a source for that? That's the first time I've heard about that and with leasing being so popular I don't really see this being true. Especially when observing people around me (Austria, Germany).
Cars previously used by businesses sold by leasing providers after 2-3 years of usage, mostly. Many of these are sold by Volkswagen Financial Services and include factory warranty. It's an easy way to get a car as good as new 30-50% cheaper.