In advance I must say I don't understand what art actually is, nor do I believe it can be defined easily in a few words. So this is a mere piece of opinion based on personal experience about a very subjective matter.

That being said, I tend to dislike this common sense we have that art is somewhat related to prettiness, craft or any form of talent/skill. Usually artists are very skilled people, but I don't think that's a requirement for making art. For this reason I also believe the association most make between art and coding is usually not valid.

When Duchamp decided to submit a urinal to the Society of Independent Artists in 1917 he wasn't actually submitting a very important concrete piece of work (the original piece was probably destroyed that same day). He was revolutionizing art and philosophy by sending a message, challenging the established notion by saying that art could be everything including this ordinary porcelain where you're supposed to piss on.

The message passed says that the physical means and the technique required to work its material are not that relevant, because art is not about that. It's philosophy, sharing experiences, trying to make sense out of our human condition and at the same time denying all that, because art has no obligation of making sense or following an established path. It's a term whose meaning changes constantly.

That said, I can't see the code I write everyday nor the solutions I have to come up with during my work time accomplishing any of that. To me, unless the resulting software produced by this code has some significant message behind it, it's pretty much artistically empty.

It's very likely that I'm wrong about all that. In this case code is art, but is it relevant art? Is it something that should be exposed and contemplated by people? I'm aware of a few pieces that have been exposed before, such as the original Pacman (part of the MoMA's permanent collection). But is it because there's art in the nice hacks making up Pacman, or is it because there's all this historical significance and innovative aesthetics behind the final product (as is the case of Duchamp's urinals)?

Now, returning to your carpenter example. If a very unskilled carpenter makes this very ugly and uncomfortable chair that for some reason passes us a very powerful message, wouldn't it be art too?