Well, Im going to give you my experience... I recently got a job for programin Bash Scripts, dealing with FTPs and lots of Linux crap Ive never dealt with before. (Including setting up servers/configurations/mail servers) And yeah... I was hired to be a "programmer". (note that I've never had experience with none of the above before)
Month and a half later I can tell you that Linux is awesome. I even installed Mint on my home desktop (Im an Android enthusiast). The best of it? ITS SUPER WELL DOCUMENTED!!! Theres NOTHING you wont find in the internet related any Unix/Linux problem/how to ect... So far I havent been assigned something that I already know how to do it, they give my my orders, I google and I come out victorious!
My biggest regret is not having learned linux in my college years.
Through my career I've learned that everything you learn is an asset to you, youll never know when you are going to use it again for professional o personal matters. So go ahead make the jump, you are doing your professional career a favor.