I agree with your assertion that 1 year isn't enough to do more than scratch the surface of a language. However, I also agree with the author that learning new languages add to your primary skill set. A new language provides the framework for exploring new ways to look at things. You may be using the term concept to represent this idea.
The atomic detail of assembly, the procedural nature of C, the set orientation of SQL, the macro focus of TeX have all given me new ways to look at problems that have paid off in my Perl programming. I don't think I would have developed these perspectives without the framework provided by these languages. I do most of my work in Perl and SQL but every now and then, I will try to solve a small problem using another language/tool just for the experience. It usually pays off.
I won't say I've learned a language a year but, it is amazing how much you do pick up a little at a time. Now that I think of it, the only language I have't gotten much out of is VB. I don't mean to knock BASIC you understand-I learned to program in BASIC-It's just that I don't think I've gotten much out of recent versions. I learned more from LOTUS 1-2-3 HAL than I ever have from Excel VBA (I know VB and VBA are not quite the same thing but the point is still the same).
The real strength I've found is to develop an approach that fits you and then grow that style to handle new and varied problems. ( a somewhat more expansive variation of zentara
's one punch philosophy )
use strict; use warnings; use diagnostics;