Why is everything on the web has to serve some random tinkerer who do not benefit the creator of the website in any way? How about we apply this thinking to oth

Why is everything on the web has to serve some random tinkerer who do not benefit the creator of the website in any way? How about we apply this thinking to other kind of products? An app has to be designed for tinkerers to? A cars, a rockets?..., so everything has to be open source? Why?