"When you’re a carpenter making a beautiful chest of drawers, you’re not going to use a piece of plywood on the back, even though it faces the wall and nobody will ever see it. You’ll know it’s there, so you’re going to use a beautiful piece of wood on the back. For you to sleep well at night, the aesthetic, the quality, has to be carried all the way through."
That's not actually true. You'll use the plywood because it's stronger and because it's not seen. You get both the cost savings and increased structural stability, which will get you more customers.
That's not the point Steve Jobs was making. The point is: if you care about what you do, you'll do your best even when you don't have to. Because as far as you're concerned you do have to.
Steve Jobs was a well-known woodcarver and carpenter. When he wasn't at Apple, he was usually found in his garage, finishing off a new wardrobe or a sturdy deck chair.
I believe it was sarcasm intended to show that just because Steve Jobs gives an example in a field he has no experience in doesn't mean you should take it literally.
Craftsmen absolutely think about what's stronger and more durable, not just what's nicest looking (especially for non-visible parts!). I've got a few pieces of pretty decent antique furniture that's made its way down to me in my family (stuff made by craftsmen, not by mass production), and the hidden pieces aren't finished or styled to the same degree as the front ones. The purpose of the back and other non-visible parts is to hold stuff together, not to look nice. I would also point out, from your own link, the specs for their "the ledge":
"available with a solid domestic walnut top, sides and doors with a plywood bottom and low voc finish or painted mdf."
(Of course, these little details about what's "the right way to do it" are rather irrelevant to the greater point, which is that if you're the type to want to do things the right way, you're going to do things that way. Just don't hate on plywood, it has its uses (and feel free to come up with the programming equivalent!))
Edit -- some more notes on plywood: a sizable piece of plywood (like for the back of a chest of drawers or bookshelf) is going to be stronger (especially with regard to bending, IIRC) and vastly cheaper than a solid piece of wood since it only needs thin pieces of veneer with good grain for the outer layers. And IMO, it looks nicer than having several individual solid-wood boards jointed together in parallel.
We have some amazing antique Persian and Korean chests in the house. Hand carved and split grain matched fronts and maybe sides, but the backs are plain and/or rough hewn. These pre-date plywood, but the same goes - don't waste effort on parts that will never be seen, just build them to do their job.
It's "strong enough" and very light to ship. That's the only reason.
It's not strong enough for a lot of tasks and is definitely not good quality. One water spill and throw it away as the laminate just peels off - even on the expensive stuff.
I've taken to buying second hand good quality furniture (which is usually available at the same price as the shitty Ikea stuff) and stripping and painting it.
NeXT went on to go broke and sell their factories for pennies on the dollar, becoming synonymous in silicon valley with excess where it isn't required
edit: for those that don't know, that jobs quote is in reference to why they put so much effort into their factories, which really were ridiculous.... jobs went on to just outsource everything after his return to apple
Perhaps a better analogy was made by (General Sir Peter de la Billiere I think) about UK troops patrolling in Helmand Province.
He said something like "Even when they think no-one is watching, no sargents, no generals, they still monitor their surroundings, check the garden walls as they pass. No-one is letting the monotinity reduce their awareness."
In short, if there is a job worth doing, its worth doing well.
Doing your duty in the military is serious business, especially in a war zone with insurgents, everyone's life is on the line. So your quote isn't an apt analogy to furniture or software interfaces. Not all jobs are worth doing well, many are worth doing "well enough" given budget,time constraints and no lives at stake.
(Not to be too harsh, but I'm speaking from the experience of having been in the military and having spent years in the software industry.)
Part of it's high quality polish and finish is the lack of seams and protrusions and screws. This necessarily means something that's difficult to open up.
You can make an argument that they made the wrong trade-off between aesthetics and pragamatism, but for the trade-off they made, they executed well.
-Steve Jobs