Embedded software can be very tightly written, with large sections of code written in assembly to save a few instructions, and other portions of code loaded into RAM for faster execution.

There are also quite a few programmers who couldn't 'cut it' in web programming, and went over to embedded, where they wreak havoc on small low-cost devices, and another group of programmers who somehow 'fell into' embedded programming many years ago, and have not updated their skills since.