I don't disagree with your premise, but there can be utility to trying out a number of different languages quickly and see which approaches resonate with you. A month with a language won't give in-depth knowledge of a languages' strengths and weaknesses, but it will allow one to move past the superficial differences (syntax, originally intended problem domains) and on to the philosophical ideas behind the language.

Trying Prolog, Erlang, Haskell and Scala in the space of 4 months while trying to solve simple problems (Project Euler comes to mind) should allow one to find a language approach that works. Object-oriented, lazy functional, concurrent or logical, one of those might stick. And if not, there's Lua, Ruby, Groovy, C#, Scheme, Perl6, Python3, Forth, C++, Brainfuck, ...

Each language has a core idea or two that could fit someone's personality. Then, the next year could be spent learning that language in-depth, as you mention. Finally, build upon that experience and re-evaluate the orignal list of languages; JavaScript looks better after Lua, Haskell is Scheme with Prolog-like pattern matching and a generic type system like an advanced C++, Forth and Brainfuck are about a simplicity even beyond Scheme's, etc.