a.) Vinyl siding is so permanent that you never have to paint it and rarely have to perform maintenance; or
b.) Vinyl siding--once it's there, it's like a disease or scourge because it will never go away.
It may be a little of both. Both more a.) than b.), I'd say. You often hear vinyl siding salesmen say this kind of thing as a way of promoting the product. Because vinyl is used in many other home remodeling projects (vinyl fence, vinyl flooring, etc.), you could also apply the "vinyl is final" idea to that, as well.

