"A love of nature keeps no factories busy" (Brave New World, 23).
Aphorisms make brief and clever observations about generally accepted truths, and the society in Brave New World has an entirely different set of aphorisms than we do. Looking at the maxims of a culture is a good way to find out what that culture values. In this case, the aphorism reveals the high value this futuristic world places upon systematic work.
Additionally, it sharply contrasts with the general value that our society places upon appreciation and awe of the world. I'm not the guy who's going to venture to Colorado to feast his eyes on nature's bounty, but obviously, that kind of thing is socially acceptable for us. I do think that there are many things radically more important than keeping factories busy -- creativity is the most stunning part of human consciousness.
And I'm pretty sure that these people are basing their calendar on the life of . . . "Our Ford." Yeah, that's weird to think about.
Amazingly, all of my paragraphs start with the letter A. It wasn't even intentional the first four times!