Several months back, the New Yorker ran a fascinating article about elevators that explored multiple issues--engineering, architecture, ethnography, economics--and shed light onto the "why" of the elevator design problem we featured in a recent episode of The Drawing Board.
In elevatoring, as in life, the essential variables are time and space. A well-elevatored building gets you up and down quickly, without giving up too much square footage to elevator banks. Especially with super-tall towers, the amount of core space that one must devote to elevators, in order to convey so many people so high, can make a building architecturally or economically infeasible.
As designers we can be dismissive about the why behind the problems we encounter; it's often enough for us that an interaction feels patently hostile. At best we file it under "implementation model" and move on; at worst we assume those design decisions don't have any rationale behind them and neglect to consider it further.
It's easy to become jaded after seeing so many examples of poorly-made software, and while it's possible to come up with a decent solution without digging any deeper, it's critical we understand the why if we really want to marshal the potential of technology to serve human needs. Also, besides informing our work, exploring the whys often reveals fascinating stories that give us insight into the underlying processes, and help us sympathize with the people that created them.