Most projects use C because there was zero consideration for anything else. No embedded team sits down at the beginning of the project and says "should we use lisp?". It's just C. Or maybe "C, but use a C++ compiler with less UB".
Indeed, if one moves into maker community there have been Basic, Pascal, Oberon, Java compilers for ages.
Those companies manage to stay in business selling such compilers for at least three decades now, which kind of proves there is a market of people willing to pay for them, instead of going with C like everyone else.
