Again: not an anti-Scala person, just turning the economics of this around in my head. That said:
Ruby is our house language. We've never hired anyone that came in the door knowing Ruby. We have a very high bar for hiring (typical first project: "write a programmable symbolic debugger for closed-source binaries on platform Y"). It takes people at least a week to become facile with Ruby --- a famously easy language to learn. Reading isn't writing.
If you have a house style, easily figure another week to pick up the right idioms, so that your code survives in the repository and isn't just refactored out.
Ruby is our house language. We've never hired anyone that came in the door knowing Ruby. We have a very high bar for hiring (typical first project: "write a programmable symbolic debugger for closed-source binaries on platform Y"). It takes people at least a week to become facile with Ruby --- a famously easy language to learn. Reading isn't writing.
If you have a house style, easily figure another week to pick up the right idioms, so that your code survives in the repository and isn't just refactored out.