Building "some kind of robot" takes considerable knowledge about what you want to achieve, what building blocks to use and how to put them together.
Building a database server with a SQL interface, network connectivity, multiuser capability, proper ACID, good concurrency properties and so on and so forth takes considerable knowledge about what you want to achieve, what building blocks to use and how to put them together.
You don't just slap complex software together, just like you don't just slap complex hardware together. You have to start small (remember how proud you likely were the first time you got the computer to do something like ask you for your name and then print it back out?) and only then expand your knowledge. It's easy to make a small piece of software that does something semi-interesting, but it's also not very hard to do the same with electronics.
So, I would argue that there is really very little difference between the examples you list, only between what appears to be your expectations on where to start. The only real difference I can think of is that with hardware, if you miswire something you risk letting the magic smoke out, whereas with software you are unlikely to get more than a compile-time or run-time error message, which means that with physical hardware, you have to be more careful before you apply power (akin to hitting the "run" button).
Also, there is electronics simulation software out there, where you sit in front of the computer to draw up a circuit diagram, hook up a power supply, and click the equivalent of "run". I've used such software something like ten years ago; it would tell me if I had made a mistake that affected the electrical viability of the circuit, such as forgetting a ground connection somewhere, and it let me see how the circuit behaved (including changing the rate of time - no need to wait an hour to see what happens then, just set the time acceleration to 60x and wait one minute). Several such software packages are sophisticated enough that you can go pretty much from idea to ready-to-make PCB without having ever gone near a soldering bench or a wire board. Granted, they aren't cheap, but then again neither is something like the professional versions of Visual Studio.