Is it a relatively small niche, though? Anything that has a microcontroller needs embedded software written for it, which is a large and growing market of smart devices and doo dads. It's not as large as the web, but it's hardly a small niche.

The reason I'm interested in it is it's the opposite of the web. It requires small, deliberate programming as opposed to the bloat fest web programming has become. It's also physical, whereas web programming is entirely non-physical. After spending so much time in these digital worlds I've been a part of, I want to build real, physical things.