Java is a bit different though. Whatever we think of 'enterprisey', it does mean that a lot of systems were built with it with the expectation it would be around a long time.
As far as 'bets' go, it's also a bet on oneself. The skills of an 'average' developer between two languages can have notable differences in concepts and requirements. i.e. I'd be a bit curious about an 'Average' C/C++ Developer who couldn't write a linked list (or at least groks them), versus an 'Average' C# or Java developer who may never have to write one in their career.
I'll say that unless you intend to be a hardcore Systems developer or Finance Sector, Javascript is never a bad thing to at least learn enough of to at least pass equality questions on interviews.
The nice thing about learning other languages however is that it may help expose you to patterns you don't normally see in your main language, or may expose you to things that make it easier to understand certain concepts (i.e. doing Javascript sites with KnockoutJS helped me learn better MVVM practices, as well as concepts like observables which I could then use back in C#)
As far as 'bets' go, it's also a bet on oneself. The skills of an 'average' developer between two languages can have notable differences in concepts and requirements. i.e. I'd be a bit curious about an 'Average' C/C++ Developer who couldn't write a linked list (or at least groks them), versus an 'Average' C# or Java developer who may never have to write one in their career.
I'll say that unless you intend to be a hardcore Systems developer or Finance Sector, Javascript is never a bad thing to at least learn enough of to at least pass equality questions on interviews.
The nice thing about learning other languages however is that it may help expose you to patterns you don't normally see in your main language, or may expose you to things that make it easier to understand certain concepts (i.e. doing Javascript sites with KnockoutJS helped me learn better MVVM practices, as well as concepts like observables which I could then use back in C#)