You are wrong. Linux has nothing to do with this. And your perception about Job market is worrying. Java is still one of the most sort after language in Job market and knowing one framework in it will be a big boost in your profile. Try to learn one each, one static and one dynamic typed language and you are good to go. Oh, and adding one JS MVC framework will further enhance your profile. So for what I said, it doesn't matter what OS are you using.