Yeah, for example, in the entirety of Dishong Tower, only 2 brass faucets exist; the rest are iron.

In addition, only one type of light (maybe 2) give you brass, but they only exist in a few POI's, and even then, they only give you 10-15 brass.

Hence the clamoring for new sources of brass. (Besides, brass doorknobs coming from doors did exist in previous alphas, but this feature was removed prior to A15.)
I make a similar stance with pathway designs. Yes, they are more intuitive, interesting, and complicated than any tower, wall, or castle design ever will be, but they are also the easiest, the cheesiest, and most exploitative designs out there. There's nothing wrong with them, but I disagree with those who state that they should be the end-all-be-all. Variety. If you want to build a castle, go for it. Yes, you'll have to work for it, you may make mistakes, you may have to deal with a breach, but that breeds experimentation, innovation, and another source of fun / another challenge.