This is why I think learning new marketable skills should be everyone's hobby. Also, in our field or any professional field, you really should be very financially secure after 50 so that a job loss doesn't hurt you.
So you learn on your own time. But since you're doing tutorials and what not, and your time isn't infinite, when you actually apply for a job with this new skill your potential employer is going to wonder why he should pay you expert wages for a skill with which you still have effectively no professional experience.
Solution: don't want to work for them anyway.
But generally, I see it as an advantage.