I heard this so many times before about just another language... learning language itself? yes, can be done damn fast, plus everybody had some java-like language in their studies. Knowing this means almost nothing, we're talking about very junior-level resource.
You know gazillions of frameworks to achieve everything these days, their integration tricks, various app servers, CI toolsets and so on and on?
I mean, if you are senior in something, are you senior also in XXX language, meaning I give you spec, we talk and you deliver proper maintenable solution, leading dev team, managing all issues and bumps along the road? If no, and you just come as described junior, nobody has time to babysit you for weeks/months, and you are not willing to take junior salary. but that's what you are to the company.