I'm a pro 3d artist (not because I'm the best here but just because i sell my artworks in the professional market).
I'm not a nostalgic, I know that the time moves on, and I use every kind of software (old or brand new) media to achive my goals... but I hate to go out for shopping using an aircarrier.

Somtime sophisticated Poser models are also unuseful in order to achive the artistic result that I want.
In the case of my Viper pilots, Posette and Dork was perfectly fitted for the roles.
So i still want to use Posette and Dork when they are useful. When they are not I use different  (moderne?) "poser people".
But I don't want to be never be able to use "old people" again just because they, their textures, props, accessories, hairs and so on are disappeared.

Anyway, where is all the old P4 stuff???
Is it pemantely deleted from servers worldwide???

And YES, I agree with dphoadley!
most of those who insists on such apologetics (read as "new is always better") usually have a financial intrest protect and justify.