while i fully understand that people want to be able to specialize everything when it comes to playing this game in solo.. since without the ability to do everything..well... you can't do everything.
however, I am sure that TFP would much rather see this game in a multiplayer enviroment where there are more than just one survivor left in the world (there has to be more than one, who would fly the supply plane (in fact.. who DOES fly that plane.. there should be some end-game where you can get back to true civilization...) -ahem sorry to digress- that being said, with MANY survivors everyone would be more compelled to work together to trade products to each other...
you see, unless of course you are from Golgafrincham, civilization still needs hairdressers, tired TV producers, insurance salesmen, personnel officers, security guards, public relations executives, management consultants...