There is your problem.If you cant learn anything else pretty sure you havent the skills to program any "embedded device".
That way you can get a clean separation of the front and back ends, and the web developers get to work with exactly the tech they are used to.
EDIT: Another possibility is that they already had PHP devs working on their corporate site or whatever, and they wanted to use them instead of hiring another team.
How did you arrive at this conclusion?
Someone with only one language or a "main language" is someone who just simply has a lower level of skill than is needed for embedded programming- which requires lots of different skills and languages. Being able to learn more than one thing is a prerequisite.