I am a big Haskell fan but no, just, no. That would be a terrible idea because of how inherently unpredictable lazy evaluation is. Replace "Haskell" with OCaml or SML though, and I definitely agree.

Also as others have commented there are usually special requirements for embedded systems that may even occasionally require one to drop down to assembly (e.g. to get the code in the right place to execute if you're on bare metal).