What happens with these concrete homes if new technology is introduced in the future? For example, what would you have to do if 10 years from now you'd want to install fiber optics throughout the house?
As for sparks .. it's actually more common than you think. Electrician/plumbers run their wires first, then the gypsum board guys come in and put it up. Well guess what happens when the electrician pulls the wire to close to the edge of the wood??? You get gypsum board screws that go right through electrical wire!! Or when a home owner decides to use really long nails to put up a picture, and hammers right through an electrical wire!! It's actually law now to use special breakers in the pannel that detect this sort of situation, and turn off on its own.
The only time you'd see steel pipes in commercial applications is if you see the wire .. If the wire is in the wall, you don't need to put it in any conduit. Again, this is safety for fires. Plastic burns easily, the steel pipes slow down the fire from spreading (try burning a coke plastic bottle .. it will burn for longer and hotter than paper!)
Back in the 1970's, copper was very very expensive. It was common to use aluminium wire. Over the years, people tended to tie aluminium with copper (which is a huge no-no as you can't mix copper with any other metal). For example, in my house, I found this in the basement. The boxes were all black on the inside (i.e. electrical fire!) But because it was a metal box, it kept the electrical fire within.
Plastic on the other hand melts at much lower temperature. Plastic also releases toxic fumes that can knock a person out long before the fire kills them. This is why, for example, in high rise buildings, it is illegal to use PVC/ABS for plumbing .. it must be copper/brass! It prevents fires from one unit spreading to the next via the plumbing stacks.
The point of all of this is that electrical fires are a lot more common than one would want to believe .. I'm sure if my house was poured concrete I could have a camp fire in the middle of the kitchen floor.

But instead, it's all wood framing, with gypsum board, and hardwood floors throughout the entire house.