The problem with all of these, with the exception of Rust and Ada, is that it's hard to do things like, get at pointers directly, for example. For all of the abstractions OCaml and Java bring, there is an often large performance penalty to pay, and when you're pass producing an embedded product, that's money you're leaving on the table because you're asking for more compute power than you actually need to get the job done. Ada is usually a pretty good choice, but it's hard to find developers outside of the defense industry; Rust on the other hand is often view (perhaps rightfully so) as still experimental and unproven.