Symbolism, Imagery, Allegory
Industry and technology are definitely celebrated in The Fountainhead. This book might star a bunch of wealthy people, but, like a presidential candidate on a stump tour, it tries to act like the working man's BFF. Check out this quote about Mike, a blue-collar worker:
People meant very little to Mike, but their performance a great deal. He worshiped expertness of any kind. [...] He was a master in his own field and he felt no sympathy except for mastery. (1.7.128)
Manual labor, and people doing the "dirty" work of creation are looked upon very favorably in this novel. Industry and technology represent things like skill and practicality, with strong people like Mike embodying this idea of skilled labor. Mike has mastered his trade and doesn't care what people think about him. He is, therefore, almost as awesome as Roark.
Roark too is always praised for his willingness and his ability to get his hands dirty. He's not just an idea man; he understands building from the ground up. Roark works a series of "dirty" jobs over the course of the novel, and his ability as a worker earns him respect from friends like Mike.
Industry and technology also represent the book's idea of progress and achievement: progress and achievement are always a good thing. And while this is a book of ideas, physical and material achievement is also celebrated. Roark is great because he designs and builds things that are useful and beneficial, like his resort in Vermont and the world's coolest gas station.